j 


UNIVERSITY  OF  CALIFORNIA 

AGRICULTURAL  EXPERIMENT  STATION 

E.  W.    HILGARD,   DIRECTOR 


NATURE-STUDY  BULLETINS 


BUTTERFLIES 

By  C.  W.  WOODWORTH 

THE  LIVING  PLANT 

By  W.  -J.  V.  OSTERHO 


PUBLISHED   BY  THE 

UNIVERSITY  OF  CALIFORNIA 

BERKELEY 

For  Sale  by  the  Students'  Co-operative  Society 

Ten  Cents  a  Copy 


UNIVERSITY  OF  CALIFORNIA 

AGRICULTURAL   EXPERIMENT   STATION 

E.   W.    HILGARD,    DIRECTOR 


NATURE-STUDY  BULLETINS 


BUTTERFLIES 

By  C.  W.  WOODWORTH 

THE  LIVING  PLANT 

By  W.   J.  V.    OSTERHOUT 


THE   UNIVERSITY  PRESS 

BERKELEY 
September,  1900 


PREFACE. 


The  Experiment  Station  desires  to  secure  the  enlistment  of  many 
volunteer  observers  in  all  parts  of  the  State,  and  hopes  by  their 
cooperation  to  be  able  to  solve  many  problems  of  value  to  agriculture 
which  it  would  otherwise  be  unable  to  approach.  For  instance,  we 
desire  to  determine  the  chacteristics  and  boundaries  of  the  agricultural 
regions  of  the  State,  and  to  do  this  must  learn  of  the  distribution  of 
plants  and  animals,  and  their  abundance  and  behavior  in  every  locality. 
Suggestions  of  the  observations  we  are  trying  to  make,  and  desire 
others  to  help  us  make,  will  be  found  scattered  very  abundantly  through 

these  bulletins. 

i 

For  this  cooperation  we  must  look  to  the  school  rather  than  to  the 
farm.  This  Bulletin,  therefore,  and  those  that  may  follow  in  this 
series,  are  addressed  to  the  teachers  of  future  farmers  rather  than  to 
the  farmers  themselves.  For  this  reason  they  will  not  be  distributed  to 
those  on  the  general  mailing  list  of  the  Station,  but  will  mainly  be  sent 
to  teachers  and  others  directly  interested  in  nature  study.  The  subject 
matter  will  not  be  directly  the  immediate  problems  of  agriculture,  but 
rather  the  underlying  principles  and  the  object  to  be  attained;  not  the 
direct  teaching  of  useful  facts,  but  the  development  of  the  power  of 
discovering  these  facts  for  one's  self.  The  development  of  these  powers 
of  observation  and  judgment  will  be  essential  to  success  in  the  coming 
farmer.  Those  who  have  interested  themselves  most  deeply  in 
searching  for  effective  means  of  promoting  the  agricultural  interests 
of  the  country,  have  quite  uniformly  reached  the  conviction  that  the 
effort  must  begin  with  the  child.  The  farmer,  of  all  men,  should 
have  an  unblunted  sympathy  and  love  for  nature  in  all  her  forms  and 
moods.  "The  man  with  the  hoe"  needs  but  the  love  of  nature  to 
change  his  mere  existence  into  a  life  of  hope  and  joy.  In  other  words, 
it  is  preeminently  desirable  that  nature  study,  which  is  beginning  to 


274411 


be  so  prominent  in  the  best  of  the  city  schools,  should  be  still  more 
developed  in  the  country  school.  Nature  study  is  a  very  different 
thing  from  the  natural  sciences,  as  they  have  usually  been  taught  and 
considered.  The  student  should  be  taught  to  view  an  insect,  for 
instance,  not  with  the  eye  of  a  zoologist,  but  rather  as  a  fellow- 
creature  whose  life  and  world  thus  become  objects  of  sympathetic 
interest.  It  is  not  an  object  to  be  dissected  or  analyzed,  but  one  that 
lives  and  influences  and  is  influenced  by  every  other  life,  object,  or 
force  with  which  it  comes  in  contact. 

Teachers  generally  feel  that  they  are  not  prepared  to  "give  the  best 
instruction  in  nature  study,  even  though  they  have  given  much  atten- 
tion to  the  various  sciences.  Fortunately,  however,  they  need  but  to 
catch  the  spirit  of  the  investigator,  and  nature  study  teaches  itself. 

Little  or  no  time  need  be  assigned  to  this  subject  on  the  schedule, 
since  it  can  be  made  to  contribute  its  influence  to  the  enriching  and 
brightening  of  all  the  work  of  the  school.  How  this  can  best  be  done 
will  always  be  a  problem  for  each  teacher  to  solve  for  himself.  The 
suggestions  here  made  are  given  in  the  hope  that  they  may  aid  teachers 
by  pointing  out  matters  for  observation  and  methods  of  study. 

(E.  W.  H.) 


BUTTERFLIES. 


By  C.  W.  WOOD  WORTH, 
Assistant  Professor  of  Entomology, 


TABLE  OF  CONTENTS. 


The  Study  of  Butterflies. 

Distribution  of  Butterflies. 

Habitat;  Geographical  regions;  Seasons. 

Daily  Life  of  Butterflies. 

Sleep;  Flight;  Method  of  walking;  Feeding;  Social  life: 
Enemies. 

Life  Histories  of  Butterflies. 

Egg  laying ;  Hatching ;  Feeding ;  Food  plants ;  Growth ;  Moult 
ing;  Social  habits;  Nests;  Pupation;  Emergence;  Ene- 
mies and  dangers. 

The  Collecting  and  Breeding  of  Butterflies. 
The  Butterflies  of  California. 

Nymphalidse;  Lycaenidae;  Papilionidae ;  Hesperiidse. 


THE  STUDY  OF  BUTTERFLIES. 


There  is  so  much  about  insects  to  excite  one's  interest 
that  they  are  peculiarly  available  for  nature  study,  and 
among  insects  the  butterflies,  by  their  conspicuousness  and 
beauty,  fitly  occupy  the  first  of  the  series  of  Nature  Study 
Bulletins. 

DISTRIBUTION    OF    BUTTERFLIES. 

Habitat. — Almost  everyone  if  asked  where  butterflies 
are  to  be  found  would  answer,  everywhere;  but  on  second 
thought  would  readily  admit  that  they  are  by  no  means 
uniformily  distributed:  they  may  be  abundant  at  one  spot 
and  rarely  or  never  found  in  another  situation.  We  are 
thus  met  at  the  beginning  of  our  study  of  butterflies  with 
this  problem:  How  can  we  explain  the  habitat  of  butter- 
flies, or  the  preference  they  exhibit  for  certain  situations? 
Perhaps  after  a  little  thought  we  may  say :  Butterflies  live 
on  flowers;  so  that  where  flowers  are,  there  we  will  find 
butterflies.  If  we  begin  to  study  the  matter,  however,  we 
will  very  soon  see  that  the  facts  cannot  be  so  easily 
accounted  for.  The  same  plant  may  sometimes  be  present 
over  a  great  part  of  the  country,  and  yet  a  certain  kind  of 
butterfly  that  feeds  upon  it  can  be  found  in  only  a  very 
limited  locality.  If  we  begin  to  collect  butterflies,  we  will 
find  that  there  is  a  certain  field  or  valley,  or  certain  hillside, 
where  we  can  find  a  kind  of  butterfly  that  we  may  not  see 
elsewhere.  Perhaps  there  are  two  or  three  localities  where  it 
occurs,  and  nowhere  in  the  intermediate  regions.  The  same 
problem  occurs  if  we  begin  to  study  any  other  animals  or 


plants;  so  that  in  studying  butterflies  we  may  learn  much 
that  will  enable  us  to  understand  the  distribution  of  manj^ 
other  forms  of  life.  Sometimes  a  crop  will  fail  at  one  place 
and  succeed  in  another,  and  we  may  from  these  butterfly 
studies  become  able  to  understand  why.  Much  remains  yet 
to  be  learned  about  the  habitat  of  animals  and  plants;  and 
it  is  possible  for  any  one,  even  a  child,  to  make  real  con- 
tributions to  our  knowledge  of  this  subject.  Butterflies 
are  particularly  useful  for  the  study  of  habitat,  because  they 
are  conspicuous  and  therefore  easily  observed. 

The  study  of  habitat  will  have  to  be  done  out  of  doors, 
and  will  add.  much  to  the  pleasure  of  the  recess  or  noon 
hour;  and  the  recording  of  observations  can  be  made  use  of 
in  the  writing,  language,  or  drawing  exercise  following. 

A  good  way  to  proceed  in  the  study  of  habitat  is  to  make 
a  map  of  the  region  studied;  it  may  be  the  school  district 
or  a  farm,  or  some  waste  land  near  the  school  house.  On 
this  map  mark  in  blue  each  place  where  the  butterfly  that 
is  studied  is  to  be  seen  abundantly,  and  in  red  those  parts 
which  it  seems  to  avoid;  then  the  uncolored  places  will 
represent  the  territory  over  which  it  flies,  but  does  not 
become  abundant. 

After  this  is  done,  a  study  of  the  plants,  of  the  eleva- 
tion, of  exposure  to  the  sun  and  winds,  the  character  of  the 
soil  and  the  moisture  contained  in  it,  may  give  a  clue  to  the 
reason  for  the  distribution. 

Independent  work  by  different  pupils,  afterwards  com- 
pared, will  assist  in  getting  them  to  make  accurate  obser- 
vations; and  studies  upon  different  species  of  butterflies 
will  aid  in  overcoming  the  tendency  to  reach  too  hasty  and 
unproved  conclusions.  Every  butterfly  will  differ  some- 
what in  its  behavior  and  produce  problems  peculiar  to 
itself;  but  all  will  contribute  to  our  knowledge  of  the 
principles  upon  which  depend  the  preferences  of  these 
creatures. 

Geographical  Distribution. — A  few  kinds  of  butterflies 
are  to  be  found  over  a  large  part  of  the  world,  but  most  of 
them  are  not  widely  distributed,  often  being  found  only  in 


a  few  places  and  perhaps  even  there  rarely.  Usually,  how 
ever,  an  insect  which  is  rare  in  one  place  may  be  very 
abundant  in  another.  The  study  of  the  geographical  dis- 
tribution of  insects  is  sure  to  aid  in  the  study  of  the 
distribution  of  other  organisms,  especially  plants.  By  it 
we  hope  to  learn  how  to  judge  of  the  adaptability  of  new 
localities  to  any  new  plant  that  maybe  introduced,  to  know 
how  widely  a  noxious  weed  or  injurious  insect  is  likely  to 
spread  and  become  troublesome.  California  is  a  wonder- 
fully good  State  for  the  study  of  distribution,  because  we 
have  so  many  distinct  climatic  regions.  One  needs  often  to 
go  but  a  few  miles  to  find  the  insect  inhabitants  quite 
different  in  their  relative  abundance,  and  sometimes  even 
they  may  differ  in  kind  also.  The  accompanying  map  of 
California  (Fig.  1,  page  10)  gives  an  idea  of  the  principal 
geographical  regions.  In  a  mountainous  country  like  this 
the  elevation  is  the  most  important  consideration  for  the 
division  of  these  regions.  The  boundaries  of  the  regions 
are  not  given  because  we  do  not  yet  know  enough  about  the 
subject  to  outline  them  accurately.  Everyone  can  aid  in  this 
study.  We  want  to  know  in  each  locality  what  butterflies 
are  present,  what  time  of  the  year  they  are  flying,  when 
they  become  most  abundant,  and  how  abundant  each  kind  is 
as  compared  with  other  kinds. 

The  gathering  of  these  facts  will  give  occasion  for  the 
making  of  many  observations  on  the  habits  and  peculiarities 
of  butterflies,  as  suggested  in  subsequent  pages  of  this 
Bulletin. 

It  is  entirely  practicable  to  attempt  a  study  of  the  dis- 
tribution by  means  of  correspondence  between  schools. 
The  practice  in  letter-writing  would  give  ample  reason  for 
establishing  such  correspondence;  and  nothing  will  con- 
tribute more  effectively  to  a  practical  knowledge  of  the 
geography  of  the  State  than  the  attempt  to  make  out  the 
distribution  of  a  butterfly. 

Seasons. — We  do  not  see  the  same  kinds  of  butterflies  at 
different  seasons  of  the  year.  There  is  one  lot  that  is  with 
us  all  winter,  and  flies  every  warm  day;  then  there  is  a  set 


10 


Fig.  1.— Map  of  California,  showing  geographical  regions. 


11 

that  comes  out  very  early  in  the  spring,  fresh  and  bright, 
contrasting  strongly  with  the  dingy,  battered  winter  butter- 
flies; and  as  spring  advances  still  other  forms  begin  to 
appear.  Thus  there  is  a  sort  of  a  procession  of  butterflies, 
each  kind  having  its  time  for  appearing  and  disappearing. 
Some  kinds  remain  with  us  but  a  short  time,  and  a  great 
part  of  the  year  are  not  to  be  seen  at  all;  others  stay  with 
us  nearly  all  the  time.  A  programme  or  calendar  might  be 
made,  showing  the  time  of  appearance  of  all  the  commoner 
butterflies.  This  could  be  kept,  and  the  next  year  the  same 
species  could  be  watched  to  see  that  they  all  kept  their 
appointments. 

There  will  always  be  a  little  difference  from  year  to 
year,  for  some  seasons  are  earlier  than  others,  and  curiously 
enough  all  the  kinds  will  not  agree  as  to  whether  a  season 
is  early  or  late ;  so  that  one  year  one  kind  may  come  at  the 
same  time  as  another,  and  the  next  year  they  may  come  at 
different  times. 

DAILY    LIFE    OF    BUTTERFLIES. 

Sleep. — Butterflies  invariably  go  to  bed  early  and  get  up 
late;  not  every  day  at  the  same  time,  but  always  long  before 
dark  the  butterflies  are  all  gone,  and  every  early  riser  will 
have  to  wait  till  the  sun  is  high  before  he  can  see  butterflies 
on  the  wing. 

Make  out  a  table  like  the  following,  on  which  to  record 
the  observations  for  a  week;  the  making  of  the  averages 
will  furnish  an  exercise  in  arithmetic  that  will  not  seem 
like  work. 


Date:   ,  1900 

Hour  when  first  seen 

Hour  when  last  seen 

Name  of  Butterflies 

1     2 

3 

4    5 

6    7 

Average 

1J2 

3 

4 

5 

6    7    Average 

Anosia  plexippus.. 
Euvanessa  antiopa 
Pieris  rapae  
Etc. 

; 

j 

i                                   ! 

Observations  like  these  will  be  of  a  great  deal  of  value  to 


12 

the  University  in  the  study  of  agricultural  regions,  and  we 
would  like  to  receive  such  tables  from  all  parts  of  the  State. 

If  one  attempts  to  make  a  table  like  that  given  above, 
he  could  increase  its  value  by  making  a  note  of  the  tempera- 
ture, of  the  sky — whether  cloudy  or  clear — and  as  to  the 
dew,  fog,  or  wind,  or  any  other  things  that  might  affect 
their  arising  or  going  to  bed.  Everyone  ought  to  be 
taught  how  to  read  the  thermometer,  and,  if  possible,  the 
barometer  too,  and  to  make  all  the  usual  meteorological 
observations;  for  the  weather  has  a  great  influence  on  all 
creatures,  whether  animal  or  vegetable. 

Many  questions  will  occur  to  one  when  trying  to  observe 
the  sleeping  habits  of  butterflies.  Where  do  the  different 
kinds  go  when  they  want  to  sleep  ?  How  do  they  act  when 
in  search  of  a  bed  ?  What  is  the  position  of  the  body  and 
of  the  various  parts  of  the  body  after  the  insect  has  gone 
to  rest  ?  Does  the  insect  remain  perfectly  quiet  as  soon  as 
it  finds  a  sleeping-place,  or  is  it  restless,  moving  about  for 
some  time  before  going  soundly  to  sleep  ?  If  it  goes  to 
sleep  in  the  afternoon  and  stays  asleep  all  night,  would  it 
be  exactly  in  the  same  position  in  the  morning  that  it  was 
in  the  night,  or  does  it  move  about  in  its  sleep  as  we  do  f 
How  does  it  act  when  it  is  waking  up  in  the  morning  ?  All 
these  questions,  and  a  great  many  more  which  will  suggest 
themselves,  are  observations  that  can  be  very  easily  made 
upon  all  our  commoner  butterflies,  and  each  kind  of 
butterfly  will  probably  be  found  to  differ  in  some  respect 
in  his  habits  from  every  other  species;  so  the  observations 
must  be  made  on  a  great  many  kinds  before  the  subject 
will  be  thoroughly  understood.  Indeed,  there  may  occa- 
sionally be  a  good  deal  of  difference  in  habits  of  different 
individuals  of  the  same  species. 

Flight. — The  sleeping  habits  are  very  interesting  par- 
ticulars of  the  daily  life  of  insects,  but  the  habits  during 
the  active  life  are  of  even  greater  interest.  No  one  who 
has  watched  the  flight  of  butterflies  will  have  failed  to 
notice  how  at  some  times  they  seem  very  intent  upon 
feeding  upon  the  flowers;  and  at  other  times  they  seem  to 


13 

fly  with  such  a  quick,  nervous  movement  that  it  is  very 
difficult  to  capture  them,  and  they  rest  only  a  moment  on 
one  flower  and  then  are  off  to  another.  At  other  times 
they  seem  to  pay  no  attention  to  the  flowers  at  all,  but  sail 
leisurely  back  and  forth  over  the  fields;  sometimes  chasing 
one  another,  and  at  other  times  alighting  on  bare  ground. 
Probably  a  great  many  of  these  changes  of  habit  are  due 
to  the  temperature,  so  it  would  be  well  to  make  observa- 
tions of  the  temperature  at  the  same  time  that  these  things 
are  observed.  It  is  possible  that  the  readings  of  the 
barometer  would  also  give  some  explanation,  and  certainly 
the  amount  of  moisture  in  the  air  has  a  great  effect. 

It  is  a  pleasant  thing  to  keep  butterflies  in  the  school 
room.  Of  course,  they  will  stay  mostly  about  the  windows, 
but  if  the  windows  contain  plants  and  flowers,  as  all  school 
rooms  should,  they  will  by  no  means  spend  all  their  time 
fluttering  against  the  glass,  and  will,  by  their  manner  of 
flight,  show  evidence  of  many  of  the  same  mental  conditions 
as  out  of  doors. 

Manner  of  Walking. — Some  butterflies  have  six  strong 
legs  like  other  insects,  but  in  many  the  front  pair  are  very 
small  (Fig.  2)  and  of  no  use  for  walking.  Butterflies  do 


FIG.  2.— Side  view  of  the  front  part  of  the  body  of  the  butterfly,  showing  the 
legs  and  mouth  parts. 

not  walk  much  as  a  rule,  especially  while  being  looked  at; 
but  if  they  are  kept  indoors  for  some  time  they  seem  to 
become  accustomed  to  people,  and  will  walk  about  and  let 
one  watch  them  quite  closely.  Notice  the  different  positions 


14 

of  the  legs  in  the  four-footed  kinds.  Note  that  the  legs  are 
jointed,  and  how  many  of  these  joints  act  as  feet.  Observe 
how  useful  are  the  claws  at  the  end  of  the  foot.  Cause  the 
butterfly  to  walk  over  a  piece  of  glass  and  then  over  a  piece 
of  cloth  and  see  the  difference.  If  the  butterfly  is  quiet 
enough  to  let  you  do  so  without  trying  to  fly,  take  a  slender 
piece  of  wire  and  gently  raise  the  different  legs  off  from  the 
surface  on  which  it  is  standing,  and  observe  which  seems  to 
disturb  it  most.  Allow  the  butterfly  to  walk  up  your  finger 
and  notice  how  it  acts  when  it  gets  to  the  top.  Many  other 
experiments  will  readily  suggest  themselves. 

Feeding. — Butterflies  that  are  kept  in  the  school-room 
should  be  fed;  and  then  is  the  best  time  to  study  the 
method  whereby  each  can  obtain  its  food.  Provide  a  little 
dish  containing  a  thin  syrup  made  of  white  sugar;  then 
holding  the  insect  carefully  by  the  wings,  taking  a  pin  in 
the  other  hand  and  dipping  the  pin  in  the  syrup  so  as  to 
slightly  moisten  it,  but  shaking  off  any  drop  that  may  form, 
gently  insert  the  pin  about  the  middle  of  the  coiled-up 
tongue  of  the  butterfly,  and  then  it  can  very  readily  be 
uncoiled.  In  uncoiling,  some  of  the  sweetened  liquid  will 
get  upon  the  tip  and  be  sucked  up  by  the  insect ;  and  if  the 
tip  is  now  dipped  into  the  syrup  and  the  butterfly  is  at  all 
hungry,  it  will  at  once  begin  to  feed,  keeping  the  tongue  out 
though  the  pin  is  removed.  It  is  very  interesting  to  watch 
the  process  of  coiling  and  uncoiling  after  the  butterfly  has 
finished  feeding. 

After  one  has  done  this  and  is  well  acquainted  with  the 
operation,  he  may  readily  see  that  the  butterflies  in  the  field 
handle  their  tongues  in  the  same  way.  Butterflies  after 
being  kept  a  long  while  in  captivity  and  fed  from  day  to 
day,  will  soon  learn  to  take  their  food  without  any  difficulty, 
uncoiling  their  tongues  themselves  when  the  food  is  pre- 
sented, so  that  the  use  of  the  pin  to  uncoil  it  may  become 
unnecessary. 

Social  Life. — The  majority  of  species  at  some  time  dur- 
ing their  life  become  more  or  less  social.  This  is  especially 
likely  to  be  seen  in  mid-summer,  or  towards  the  fall  of  the 


15 

year;  and  one  may  sometimes  see  swarms  of  butterflies, 
often  numbering  scores  or  even  hundreds,  gathering 
together,  particularly  in  the  moist  places  in  the  dried-UD 
beds  of  streams,  or  in  other  open  bare  spaces,  where  they 
will  remain  for  hours  at  a  time,  now  and  then  flying  about 
and  then  again  alighting  in  about  the  same  place.  These 
swarms  of  butterflies  are  not  usually  confined  to  single 
species,  though  generally  one  species  is  very  much  more 
abundant  than  any  other.  Late  in  the  fall  there  is  at  least 
one  species  of  butterfly  common  in  this  State  (Anosia  plex- 
ippus)  that  has  the  habit  of  gathering  in  immense  swarms, 
reminding  one  of  the  swTarms  of  birds  that  gather  at  this 
time  of  the  year  preparatory  to  migrating;  and  it  is  thought 
that  in  this  case  the  butterflies  gather  for  the  same  purpose. 
Aside  from  the  gatherings  described  above,  the  social 
instincts  of  butterflies  seem  to  be  confined  to  the  habit  all 
have  of  flying  after  each  other  during  the  hotter  part  of  the 
day,  occasionally  three  or  four  together.  When  they  are 
taking  their  food  on  the  flowers  they  seem  to  be  annoyed  by 
the  presence  of  other  butterflies.  The  more  timid  kinds 
will  often  leave  a  blossom  at  once  if  another  butterfly 
attempts  to  alight  upon  it;  but  some  species  do  not  appear 
to  be  so  timid,  and  occasionally  two  or  three  will  be  found 
busily  working  upon  the  same  bloom,  and  paying  no 
attention  to  each  other. 

Enemies. — Butterflies,  as  well  as  other  creatures,  have 
enemies.  They  are  often  caught  by  spider  webs,  though 
as  they  are  generally  strong  enough  to  tear  their  way 
through,  they  usually  get  free.  It  seems  that  their  clothing 
of  scales  (Fig.  3)  is  particularly  useful  as  a  defense  against 
spider  webs,  for  the  web  becomes  attached  merely  to  this  cloth- 
ing; as  the  insect  struggles  the  scales  are  pulled  off  and  left 
behind  with  the  web,  and  the  insect  escapes,  scarcely  at  all  the 
worse  for  wear.  There  is  a  spider,  however,  which  occurs  in 
the  blossoms  in  some  regions,  that  is  able  to  destroy  a  large 
number  of  butterflies.  This  spider,  taking  firm  hold  of  the 
inner  parts  of  a  blossom  with  its  shorter  legs,  lies  in  wait 
for  the  butterfly,  and  when  it  comes  to  feed  suddenly  grasps 


16 


it  with  its  long  legs,  holding  it  fast  in  spite  of  all  its  efforts 
to  escape,  and  sucking  the  fluids  from  the  body.  After 
feeding  to  its  satisfaction  it  drops  the  dead  body  of  the 
butterfly  to  the  ground,  and  is  ready  to  capture  the  next 


FIG.  3.— The  clothing  of  scales,  as  seen  when  a  portion  of  the  wing  is  placed 
under  the  microscope. 

victim  that  may  come.  Butterflies  are  such  active  creatures 
that  very  few  other  insects  are  able  to  capture  them,  though 
a  certain  number  are  destroyed  when  they  are  young,  or 
getting  very  old.  Birds  probably  destroy  more  butterflies 
than  do  other  animals,  and  it  is  thought  that  much  of  the 

color  and  pattern  of  the  wings 
often  develop  as  a  protection 
against  birds.  It  is  thought, 
Iff or  instance,  that  the  brilliant 
J  colors  and  peculiar  patterns  of 
the  wings  (Fig.  4)  catch  the  atten- 
tion of  the  birds  which  for  this 
reason  try  to  catch  the  wings ;  the 
body  of  the  insect  in  such  a  case 
escapes,  and  the  worst  that  hap- 
pens is  a  small  hole  torn  in 


FIG.  4.— Wing  of  Vanessa,  show- 
ing system  used  in  naming  the 
various  spots. 


the  edge  of  the  wing.  Indeed,  one  often  captures  butterflies 
with  broken  wings,  so  torn  as  to  suggest  the  mistake  of  some 
bird.  Many  butterflies  have  entirely  different  patterns  on 
the  upper  and  the  under  side  of  the  wing,  and  it  is  sup- 
posed that  these  differences  have  been  brought  about  as  a 
means  of  protecting  the  insect.  A  brown  butterfly  flying 
along,  suddenly  becoming  gray  as  it  alights,  would  certainly 
be  very  misleading  to  the  bird  that  was  attempting  to 
capture  it.  One  of  our  commonest  butterflies  (Ccenonympha 
californica)  in  the  fall  of  the  year  is  almost  white  above,  but 
varies  from  gray  to  brown  below.  In  addition  to  the  pro- 
tective color  of  the  under  side  of  the  wing,  it  has  developed 
a  mode  of  flying  that  is  very  misleading;  the  insect  in  flying 
appears  as  though  it  were  falling  over  and  over  like  a  bit 
of  leaf,  and  finally  often,  when  alighting,  lies  on  its  side  011 
the  ground. 

LIFE -HISTORY  OF  BUTTERFLIES. 

Thus  far  we  have  been  studying  the  butterfly  only  in  its 
full-grown  form.  Everyone  understands  that  the  butterfly 
is  first  a  caterpillar;  indeed  there  are  four  distinct  stages 
in  a  butterfly's  life,  so  different  from  each  other  that  no 
one  could  tell  that  they  come  one  from  the  other  without 
actually  watching  the  transformation .  The  study  of  these 
changes  is  one  of  the  most  interesting  departments  of 
nature  study.  The  earlier  stages  of  most  of  our  butterflies 
are  still  unknown;  so  that  here  also  there  is  opportunity 
for  original  work. 

Most  butterflies  require  just  a  year  to  go  through  their 
complete  transformations,  though  there  are  some  that  have 
two  or  even  more  generations  in  a  year.  With  most  butter- 
flies there  will  be  a  time  of  year  when  only  the  caterpillar 
can  be  found;  then  the  pupa  will  be  produced,  and  later 
the  full-grown  butterfly;  this,  after  a  while,  will  lay  its 
eggs  and  die.  It  is  evident  that  the  different  kinds  of  butter- 
flies have  a  very  different  annual  programme,  because  there 
are  some  kinds  always  flying  whenever  it  is  warm  enough. 
One  might  draw  a  diagram  for  each  species,  indicating  by  a 


18 

mark  of  one  color,  the  period  in  which  the  egg  is  found, 
the  time  of  the  life  of  a  larva  or  caterpillar  by  another,  that 
of  the  pupa  or  chrysalis  by  a  third,  and  that  of  the  perfect 
butterfly  by  a  fourth.  Of  course  these  periods  would  over- 
lap each  other  slightly,  since  the  adult  insects  live  some  time 
after  the  eggs  are  laid,  and  the  eggs  do  not  all  hatch  at 
exactly  the  same  time. 

One  could  also  make  a  butterfly  calendar  on  this  prin- 
ciple, that  would  indicate  not  only  the  time  when  each 
common  butterfly  first  appeared  in  the  spring,  but  also  the 
time  of  its  greatest  abundance,  by  widening  the  line  and 
narrowing  it  again  towards  the  time  when  it  disappears. 

Almost  all  butterflies  have  peculiar  habits  or  structure, 
or  have  their  life  history  so  arranged  that  it  enables  them 
to  pass  through  the  winter;  and  as  in  this  State  we  have 
such  long,  hot,  dry  summers,  many  have  special  provisions 
for  passing  this  season.  When  the  insect  passes  the  winter 
in  one  of  its  active  forms,  the  winter  rest  resembles  in 
many  respects  the  daily  sleep  of  the  same  insect  during  the 
warmer  parts  of  the  year.  It  appears  almost  as  though  the 
butterfly  or  the  caterpillar  merely  went  to  sleep  too  soundly, 
and  so  slept  on  day  after  day;  and  in  a  good  part  of  the 
State  many  of  these  insects  that  have  thus  gone  into  retire- 
ment, come  forth  and  fly  or  walk  about  during  the  warmer 
days.  There  is  one  difference  between  the  winter  rest  and 
the  daily  rest  of  insects;  viz.,  the  fact  that  they  seem  to 
select  for  the  former  much  more  secure  and  secluded  places 
than  for  ordinary  sleep. 

Egg-laying. — The  eggs  of  butterflies  are  usually  quite 
difficult  to  find,  as  they  are  such  inconspicuous  objects;  and 
the  observation  of  the  methods  of  egg-laying  are  still  more 
difficult.  Each  species  acts  somewhat  differently;  but  if 
one  knows  the  food  plant  of  the  larva,  and  will  persistently 
follow  those  butterflies  that  are  seen  fluttering  about  that 
plant,  he  may  be  able  to  observe  the  process.  The  easiest 
kind  to  observe  for  this  purpose  is  the  common  white  cabbage 
butterfly,  that  lays  its  eggs  at  random  around  the  leaves 
of  the  cabbage-plant;  though  it  occupies  only  a  moment 


19 

in  depositing  an  egg.  The  large  orange-red  butterfly 
( Anosia  plexippusj  acts  in  much  the  same  way,  laying  also 
single  eggs,  generally  on  the  under  side  of  the  leaves  of 
milk  weeds.  Some  butterflies  lay  their  eggs  in  considerable 
masses.  This  is  true  of  the  large  black  butterfly  (Euvanessa 
antopia),  which  deposits  its  eggs  upon  the  twigs  of  elm 
and  willow  trees.  It  will  require  very  careful  work  to  note 
the  exact  process  of  egg-laying,  and  quite  careful  looking 
to  find  the  eggs  even  after  one  sees  about  what  part  of  the 
leaf  they  are  laid  upon.  Most  butterfly  eggs  are  very 
beautiful  objects  when  examined  under  the  microscope. 

Hatching. — If  one  succeeds  in  finding  the  eggs  of  butter- 
flies it  will  be  extremely  interesting  to  watch  the  mode  of 
hatching.  Usually,  the  eggs  hatch  early  in  the  morning, 
though  there  is  considerable  variation,  especially  if  the  eggs 
are  kept  in  the  house.  Usually,  there  is  a  change  of 
color  just  before  hatching,  and  the  insect  begins  to  dig  its 
way  out  on  a  particular  side  or  end  of  the  egg.  Sometimes 
the  eggshell  is  eaten  up;  at  other  times  a  hole  only  large 
enough  to  allow  the  butterfly  to  escape  is  made.  The 
method  of  making  the  opening,  the  various  efforts 
necessary  in  order  to  escape  from  the  egg,  and  the  treat- 
ment of  the  shell,  all  deserve  attention ;  also  the  appearance 
of  the  shell  after  the  caterpillars  leave  it  should  be  noted. 
The  time  necessary  for  hatching  will  be  found  to  differ  a 
great  'deal  with  different  species,  but  generally  more  with 
the  same  species,  according  to  the  vigor  of  the  young  worm, 
and  the  temperature. 

Feeding. — Very  soon  after  hatching,  the  insects  begin  to 
search  for  food.  If  the  right  sort  is  furnished,  the  insect  will 
very  shortly  begin  to  eat  into  the  surface  of  the  leaf,  and  it 
will  be  possible  to  observe  the  process  of  feeding  by  means  of 
a  hand  magnifier;  or  if  examined  very  closely,  much  can  be 
be  seen  with  a  naked  eye.  Points  especially  to  be  noted  in 
the  very  young  caterpillar  are  that  it  attacks  the  leaf  in  a 
very  different  manner  from  that  of  the  larger  insect,  that  it 
eats  from  a  different  portion  of  the  leaf,  and  that  it  requires  a 
different  length  of  time  for  a  meal.  It  will  be  very  easy  to 


20 

watch  the  insect,  to  note  how  long  the  time  between  meals, 
how  it  behaves  itself  between  the  feeding  times,  and  the  time 
occupied  and  amount  of  food  taken  at  each  feeding. 

food- Plants. — Each  species  of  butterfly  has  its  own 
peculiar  food-plants,  often  a  single  species  only;  and  it 
seems  to  be  impossible  to  make  them  feed  upon  other- 
plants.  There  are  some  notable  exceptions  to  the  rule  of  a 
single  food-plant;  one  of  our  common  butterflies,  for  in- 
stance, feeds  almost  equally  often  on  elm  and  willow,  two 
widely  different  plants.  In  most  cases  when  the  butterfly 
larva  feeds  on  more  than  one  plant,  they  will  be  very 
closely  related  to  each  other,  belonging  to  the  same  natural 
family,  for  instance.  An  interesting  experiment,  which 
can  be  tried  whenever  one  is  fortunate  enough  to  find  a 
butterfly  caterpillar,  is  to  try  all  manner  of  leaves,  placing 
them  all  in  the  same  box,  and  noting  on  which  the  cater- 
pillar will  feed.  While  it  will  generally  be  found  that  one 
or  two  plants  are  all  that  are  eaten,  the  list  can  be  made 
larger  by  confining  a  caterpillar  in  a  box  with  a  single 
plant  until  it  is  quite  hungry,  when  it  will  often  eat  things 
that  it  would  not  touch  if  other  food  was  available.  Food- 
plants  of  most  of  our  common  butterflies  are  given  in  the 
latter  part  of  this  Bulletin,  but  probably  with  experiments 
of  this  kind  the  list  for  each  species  might  be  very  greatly 
increased.  In  observing  the  manner  of  eating,  one  might 
note  how  the  insect  is  aided  in  the  process  by  its  three  pairs 
of  true  legs;  how  the  leaf  fits  into  the  mouth  in  just  the 
right  position  for  the  jaws  to  bite  off  a  piece;  how,  in  feed- 
ing, the  insect  moves  its  head  downward  towards  its  breast, 
taking  bite  after  bite  until  it  reaches  as  far  as  is  convenient, 
and  then  moves  back  near  the  starting  point  and  mows  off 
another  swath;  how  it  acts  when  it  comes  to  a  vein  in  the 
leaf;  the  difficulty  it  experiences  in  biting  into  it,  and  how 
sometimes,  if  it  is  very  large,  it  gives  up  and  leaves  the 
vein,  continuing  to  eat  off  the  thinner  parts  of  the  leaf; 
how  intent  the  insect  is  while  eating,  allowing  one  to 
handle  it  quite  freely,  and  how,  when  handled  too  roughly, 
it  takes  considerable  time  before  it  recovers  its  composure 


21 

enough  to  begin  again  to  feed;  how  much  more  it  takes  to 
disturb  it  when  it  is  hungry,  than  when  it  is  nearly  through 
feeding. 

Groivth. — Caterpillars  increase  very  rapidly  in  size. 
After  a  litttle  acquaintance  with  them  one  can  sometimes 
judge  quite  accurately  of  the  worm  by  size;  that  is,  cater- 
pillars one,  two,  or  three  days'  old  are  decidedly  different 
in  size.  Note  what  part  of  the  body  increases,  or  whether 
all  parts  increase  alike;  especially  notice  the  total  length 
as  compared  with  the  size  of  the  head  or  of  the  legs.  Try 
to  get  some  estimate  of  the  amount  of  increase  in  size  that 
is  produced  by  a  certain  quantity  of  food.  Note  that  the 
growth  of  the  insect  is  not  uniform;  that  some  days  even, 
just  before  the  moulting  periods,  it  seems  to  decrease  rather 
than  increase. 

Moulting. — The  moulting  process  just  referred  to  is  an 
extremely  interesting  process  to  watch;  how  the  insect 
comes  out  of  its  old  skin;  where  the  break  occurs;  how  the 
legs  escape,  one  by  one;  how  the  legs  are  pulled  out  with- 
out disengaging  the  old  claws  that  are  hooked  into  the 
silken  carpet  spun  by  the  worm  just  before  moulting;  and 
how  the  spines  aid  in  the  process  of  slipping  the  skin  down 
the  segments  of  the  body.  With  a  little  care  one  can  even 
notice  how  the  breathing- tubes  pull  out  through  the 
breathing-holes  along  the  side.  Most  insects  have  a  par- 
ticular time  of  day  for  the  moulting  process,  and  the 
different  moults  occupy  different  lengths  of  time  prepara- 
tory to  the  casting  of  the  skin. 

Social  Habits. — Most  butterflies,  while  young,  are  en- 
tirely solitary  in  their  habits.  Some  caterpillars,  however, 
especially  those  that  are  produced  from  eggs  laid  in  a  mass, 
are  more  or  less  social,  and  in  a  few  cases  are  distinctly 
social  insects,  living  together  throughout  their  whole  feed- 
ing period,  and  only  separating  as  they  finally  begin  to 
search  for  a  place  to  form  their  chrysalids.  These  social 
insects  move  about  at  the  same  time,  going  from  one  part 
of  the  plant  to  another  always  together;  generally  being 
able  to  touch  each  other  and  passing  over  the  same  track  in 


22 

their  migrations.  Like  other  caterpillars,  they  spin  as 
they  go  a  thread  of  silk,  which  they  attach  to  the  surface, 
so  that  they  make  quite  a  distinct  silken  pathway  by  the 
time  the  whole  colony  has  gone  over  part  of  the  stem.  Not 
only  do  the  social  insects  feed  together,  but  at  each  time 
that  they  shed  their  skin  they  all  seem  to  cease  to  feed 
about  the  same  time,  and  those  that  cast  their  skin  first 
appear  to  wait  some  time  even  for  their  slower  brethren,  so 
that  they  all  begin  to  feed  at  nearly  the  same  time.  Of 
course,  there  are  a  few  weaker  members  of  the  family  that 
fail  to  moult  at  the  time  the  majority  do,  and  after  a  moult 
or  two  they  show  very  conspicuously  among  the  others  by 
their  small  size.  As  a  rule  these  weakly  caterpillars  die 
before  they  are  fully  grown. 

Nests. — A  good  many  of  the  caterpillars  of  butterflies 
live  freely  exposed  on  the  leaves  of  plants  and  make  no 
effort  at  concealment,  but  there  are  quite  a  number  of  very 
interesting  cases  of  nest-building.  One  of  the  most  curious 
of  nests — something  which  can  hardly  be  called  a  nest — is 
where  a  portion  of  the  leaf  serves  as  a  resting  place,  and 
the  only  nest-structure  to  be  found  upon  it  is  a  little  carpet 
of  silk  to  rest  upon.  This  portion  is  separated  from  the 
rest  of  the  leaf  by  the  manner  in  which  the  leaf  is  eaten, 
and  the  position  the  insect  takes  is  such  that  it  is  splendidly 
disguised.  Most  of  the  nests  of  butterflies  are  produced  by 
sewing  leaves  together — sometimes  it  may  be  the  leaves  at 
the  upper  end  of  the  stem,  sometimes  two  or  three  leaves 
down  the  side  of  the  stem,  or  again  a  single  leaf  may  be 
bent  upon  itself  so  as  to  produce  a  neat  little  pocket  in 
which  the  insect  hides;  sometimes  only  a  portion  of  the 
leaf  will  be  folded  over— that  portion  generally  separated 
from  the  other  parts  of  the  leaf  by  the  caterpiller  eating 
out  a  narrow  strip  across  part  of  the  blade.  The  accom- 
panying drawing,  shows  one  of  the  most  peculiar  forms  of 


FIG.  5.— Nest  of  hibernating  larva. 


23 

nests,  in  which  part  of  the  leaf  serves  as  the  nest  and  the 
remainder  is  eaten  in  such  a  way  as  to  aid  in  disguising 
the  structure.  Most  of  the  nests  of  butterflies  are  for  con- 
cealment during  the  summer,  at  the  time  when  plants  and 
insects  are  both  growing;  but  the  style  last  described  is 
made  for  passing  the  winter,  and  it  will  be  noticed  that 
the  leaf  is  sewed  fast  to  the  twig  to  prevent  its  dropping 
as  do  other  leaves  in  the  autumn.  These  nest  structures 
are  not  generally  abundant  enough  to  enable  one  to  find 
them  whenever  desired,  but  as  in  many  things  about  butter- 
flies one  should  keep  a  lookout  for  them  while  rambling 
over  the  fields.  Sooner  or  later  one  will,  if  persistent,  be 
rewarded  by  finding  the  object  of  his  search. 

Pupation: — When  a  caterpillar  becomes  full  grown,  it 
moults  into  an  object  possessing  a  very  different  form. 
This  last  moult  requires  more  time  than  any  of  the  pre- 
vious ones,  and  much  more  elaborate  preparation  is  made 
by  the  caterpillar  before  entering  upon  it.  Instead  of 
making  the  silken  carpet  for  all  of  its  legs  to  stand  upon, 
it  makes  a  smaller,  but  more  perfect  patch  of  silk  for  the 
hind  legs;  and  generally,  in  addition,  makes  a  girdle  about 
the  middle  of  the  body,  attaching  it  on  either  side,  and 
holding  the  body  against  the  surface  upon  which  it  is 
standing.  Some  butterflies  do  not  provide  this  girdle,  and 
depend  only  on  the  carpet  under  the  last  pair  of  legs. 
After  this  preparation  the  skin  splits,  and  as  the  new  in- 
sect begins  to  appear,  its  difference  from  the  larva  will  be 
noticed.  The  pupa  is  without  appendages  capable  of 
movement,  though  there  really  are  legs  and  wings.  These 
lie  against  the  body  and  soon  become  immovably  glued 
down.  At  first  they  can  be  lifted,  however,  and  if  held 
away  from  the  body  until  dried  a  little,  will  never  become 
attached.  The  most  interesting  point  in  the  whole  pro- 
cess is  the  means  by  which  the  insect  finally  gets  rid  of  the 
old  larval  skin,  for  it  is  to  be  remembered  that  the  claws 
of  the  hind  feet  of  the  larval  skin  are  the  only  means  of 
attachment.  Now  in  some  way  the  insect  must  take  the 
end  of  the  body  out  of  the  larval  skin,  reach  over  and  get 


24 

hold  of  the  silken  carpet  with  the  special  claws  found  at 
the  end  of  the  pupa,  before  the  larval  skin  becomes  de- 
tached. This  process  is  not  so  difficult  in  those  forms  pos- 
sessing the  girdle;  but  when  the  girdle  is  not  present  one 
must  actually  see  the  process  in  which  this  is  accomplished, 
before  he  would  believe  it  possible.  There  is  no  better  in- 
sect on  which  to  observe  this  than  the  milkweed  butterfly 
(Anosia  plexippus) . 

Emergence :  — The  process  by  which  the  butterfly  escapes 
from  its  pupa  case  is  full  of  interest.  The  manner  of  the 
splitting  of  the  skin,  and  the  various  movements  of  the 
young  butterfly  as  it  forces  its  way  out  of  the  pupa  skin, 
the  undeveloped  wings  hanging  down,  bag-like,  from  the 
sides  of  the  young  butterfly,  and  their  gradual  enlargement 
until  they  take  on  the  full  size  and  shape  of  the  true  but- 
terfly, can  never  lose  their  interest  no  matter  how  often 
the  process  is  observed.  The  accompanying  figure  (6)  will 
show  the  appearance  of  the  chrysalis  after  the  emergence 
of  the  butterfly. 


FlG.  6.— Pupal  skin  of  Euvanessa  antiopa  after  escape  of  butterfly. 

Enemies: — Butterfly  chrysalids  are  not  very  common, 
and  the  very  unusual  shape  and  color  would  doubtless  fail 
to  give  to  the  birds  the  impression  that  it  was  a  dainty 
morsel.  If  they  were  more  abundant,  birds  might  learn  to 
recognize  them  and  hunt  for  them,  and  then  their  peculiar- 
ities would  fail  to  protect  them.  It  appears  that  no  one 
has  given  much  attention  to  the  insect-enemies  of  the  pupa? 
of  butterflies;  so  that  about  all  we  know  about  this  stage 
is  that  when  parasites  enter  the  caterpillar,  they  usually 
come  to  their  full  development  while  the  butterfly  is  in  the 


25 

chrysalis  form,  and  out  of  the  chrysalis  there  comes  the 
parasite  instead  of  the  butterfly. 

Caterpillars  or  butterflies  are  often  destroyed  in  great 
numbers  by  the  attack  of  parasites.  These  are  either  flies 
or  wasps  that  lay  their  eggs  upon  the  caterpillar ;  and  when 
this  egg  hatches,  the  little  worm  that  is  produced  burrows 
down  into  the  body,  feeding  upon  the  fat  bodies  and  ab- 
sorbing food  also  from  the  blood,  but  not  generally  caus- 
ing the  death  of  the  caterpillar  until  just  about  the  time  it 
is  ready  to  transform  into  a  chrysalis,  or  after  the  chrysalis 
has  been  formed. 

Various  diseases  often  cause  the  death  of  many  but- 
terfly larvae  and  pupae;  one  of  the  commoner  and  more 
conspicuous  of  these  is  shown  in  Figure  7. 


FIG.  7.— Pupa  of  Euvanessa  antiopa  that  had  been  killed  by  attack  of  the 
fungus  seen  growing  over  the  surface. 

Many  butterfly  larvae  have  peculiar  shapes  and  are 
ornamented  in  various  ways;  all  of  which  is  supposed  to 
have  been  developed  as  protection  against  birds  and  para- 
sitic insects.  It  is  a  curious  fact  that,  in  many  cases,  the 
young  caterpillar  is  quite  different  in  appearance  from  the 
older  specimen  that  has  moulted  several  times;  and  it  is 
thought  that  this  difference  is  a  protection  against  different 
enemies  that  are  likely  to  attack  the  caterpillar  at  different 
stages  in  its  life.  The  egg,  even,  is  not  without  its  enemies, 
for  there  are  parasites  that  attack  the  egg  and  prevent  the 
hatching.  These  parasites  go  through  their  whole  develop- 
ment within  the  egg-shell,  and  are  of  course,  excessively 
minute.  Eggs  of  butterflies,  aside  from  the  attack  of 
these  parasites,  are  generally  quite  free  from  danger  of 
insect  enemies. 


26 


COLLECTING. 

The  making  of  a  collection  is  one  of  the  best  ways  of 
developing  an  interest  in  a  subject  and  of  recording  one's 
observations.  The  method  of  making  the  collection,  and 
the  character  of  the  collection  itself,  will  depend  upon 
the  lines  of  observation  that  are  receiving  greatest  atten- 
tion. The  commonest  collections  consist  merely  of  a 
set  of  specimens  of  the  adults,  when  the  chief  interest 
centers  on  the  variety  and  grouping  of  the  insects.  When 
the  interest  has  grown  to  a  study  of  the  whole  life-history 
of  an  insect,  the  collection  is  made  to  contain  not  only  the 
adult  insect,  but  all  stages  of  its  development;  and,  as  the 
interest  grows  wider,  specimens  representing  all  phases  of 
the  insect's  activity  become  objects  for  collection.  It  is  a 
good  policy,  however,  at  least  when  Beginning  a  collection, 
to  pay  most  attention  to  some  one  class  of  views,  rather 
than  to  extend  it  equally  in  all  directions.  A  collection  of 
adult  forms  of  butterflies,  therefore,  makes  a  very  useful 
beginning;  or  one  may  be  made  to  indicate  sleeping 
habits,  or  feeding  habits  of  these  insects;  or  one  repre- 
senting the  varying  daily  or  seasonal  peculiarities  will 
be  valuable.  The  following  hints  are  given  to  suggest  a 
method  of  procedure  in  making  a  collection. 

Collection  of  Butterflies. — The  apparatus  necessary  for 
collecting  butterflies  consists  of:  first,  a  means  of  capture; 
and  second,  a  means  of  killing. 

Capturing  can  be  done  by  hand,  but  always  with  some 
danger  to  the  specimens,  or  with  loss  of  time;  so  that  a  net 
is  practically  necessary.  Nets  can  be  very  easily  made  by 
attaching  a  wire  hoop  to  the  end  of  a  stick  or  bamboo  about 
the  size  of  a  broom  handle,  and  sewing  to  the  hoop  a  bag  of 
mosquito  net.  A  hoop  about  a  foot  in  diameter  will  be 
most  convenient,  and  the  mosquito  bag  should  be  about  two 
feet  deep,  or  a  little  more.  With  a  little  practice  one  can 
become  very  skilful  in  the  handling  of  the  net,  and  may  catch 
butterflies  very  rapidly  and  certainly.  In  approaching  an 


27 

insect  it  is  well  to  wait  until  it  has  alighted,  and  to  bring 
the  net  close  to  it  as  slowly  as  possible,  and  keep  it  near  the 
ground  and  so  out  of  sight.  When  one  has  brought  it  very 
close  so  as  to  be  sure  of  his  prey,  a  sudden  quick  stroke, 
followed  by  a  quick  back  movement,  will  securely  bag  the 
butterfly  and  fold  the  net  over  so  that  it  cannot  escape. 
It  is  well  to  make  it  a  rule  never  to  touch  the  wings  with 
the  fingers  in  removing  the  insect  from  the  bag.  A  good 
plan  is  to  push  the  wide-mouthed  bottle,  used  for  killing, 
into  the  folded  net  until  it  reaches  the  butterfly,  when  the 
insect  will  flutter  into  the  bottle,  and  the  insertion  of  the 
cork  will  hold  it  a  prisoner. 

The  Killing-Bottle. — The  most  convenient  method  of 
killing  butterflies  is  the  use  of  the  wide-mouthed  bottle 
into  which  the  butterfly  can  pass  without  injury  to  the 
wings.  A  bottle  is  better  than  a  box  because  the  insect  can 
be  seen  within  and  the  cork  closes  it  tightly,  thus  permitting 
the  full  strength  of  the  killing  substance  to  act.  Cyanide  of 
potassium  makes  a  very  good  poison,  and  can  be  imbedded 
in  plaster  of  paris  in  the  bottle  and  so  be  perfectly  safe. 
Another  method  is  to  place  the  poison  in  saw- dust,  or  to  wrap 
it  in  paper;  in  both  cases  covering  it  with  a  stiff  cardboard 
or  pasteboard  fastened  to  the  bottle  by  means  of  shellac. 
Another  method  of  making  a  killing-bottle  is  to  place  in  the 
bottom  a  small  quantity  of  cotton  which  is  wetted  from 
time  to  time  with  chloroform,  ether,  benzine,  or  even  com- 
mon gasoline,  for  the  vapors  from  all  of  these  substances 
are  very  efficient  in  killing  insects.  A  butterfly  should  be 
allowed  to  remain  in  the  killing-bottle  for  some  time  after 
it  is  apparently  dead,  because  at  first  the  poison  merely  puts 
the  insect  to  sleep,  and  it  is  very  apt  to  revive  if  not  kept 
in  long  enough. 

Pinning  and  Setting. — After  the  insects  are  captured 
and  killed,  they  are  ready  to  be  pinned  and  set.  For 
pinning  always  use  insect  pins,  which  are  much  longer  and 
have  slenderer  points  than  common  pins,  and  are  not  so  apt 
to  corrode.  They  cost  about  ten  or  fifteen  cents  a  hundred. 
A  butterfly  should  be  pinned  through  the  middle  of  the 


28 

thorax,  and  in  such  a  way  that  the  body  is  at  right  angles 
to  the  pin ;  and  the  pin  should  be  thrust  through  the  insect 
far  enough  that  twice  as  much  pin  appears  below  than 
above  the  body. 

After  the  insect  is  properly  pinned  it  is  ready  for  setting. 
For  this  purpose  a  setting-board  is  necessary.  There  are 
two  styles  of  these;  in  one  a  groove  is  made  large 
enough  to  receive  the  body  of  the  insect,  and  in  the  bottom 
of  the  groove  an  awl-hole  is  made,  through  which  the  point 
of  the  pin  is  thrust;  the  wings  are  then  spread  and  pinned 
down  to  the  board  in  such  a  way  as  to  show  the  most 
possible  of  their  surface.  The  fore- wings  should  be  pulled 
forward  so  far  that  their  hind  edges  may  lie  in  the  same 
straight  line,  and  the  hind  wings  brought  to  such  a  position 
as  to  leave  about  the  same  gap  next  to  the  body  as  to  the 
front  wings.  In  pulling  these  wings  forward  a  pin  may  be 
used,  inserting  it  just  behind  the  strong  vein  and  thus 
avoiding  danger  of  tearing.  After  the  wings  are  pinned 
down  in  the  proper  position  it  is  a  good  plan  to  lay  strips  of 
paper  over  them  to  hold  them  straight;  and  it  is  possible, 
after  these  paper  strips  are  pinned  down,  to  remove  the  pins 
that  go  through  the  wings:  the  holes  they  have  made  will 
then  be  scarcely  noticeable ;  whereas,  if  the  pins  are  left  in  the 
wings  until  they  are  dry,  the  holes  will  always  be  easily  seen. 

The  other  style  of  setting-board  is  a  plain,  flat  board 
with  a  larger  awl  hole,  big  enough  to  take  the  head  of  a  pin. 
The  insect  in  this  case  is  laid  on  the  board  back  down,  the 
head  of  the  pin  projecting  into  the  awl-hole;  the  rest  of 
the  process  is  the  same  as  described  above. 

The  insects  should  be  allowed  to  remain  on  the  setting- 
board  until  they  are  thoroughly  dry,  and  this  sometimes 
may  take  a  week  or  two.  After  the  insects  are  thoroughly 
dry,  the  paper  strips  are  removed  and  the  specimen  is  ready 
to  be  placed  in  the  collection.  It  is  a  good  plan  to  write 
on  a  small  piece  of  paper  the  date  and  locality  of  every 
specimen,  and  to  pin  this  below  it. 

Breeding  of  Butterflies. — The  care  of  living  insects  is 
known  among  naturalists  as  insect-breeding,  and  serves 


29 

both  for  the  study  of  the  transformations  and  for  the  secur- 
ing of  perfect  specimens  for  the  collection.  The  most  diffi- 
cult part  of  the  process  is  obtaining  the  eggs;  occasionally 
one  will  find  them  in  the  field,  but  ordinarily  they  will  have 
to  be  obtained  by  enclosing  the  butterflies  in  a  sleeve-like 
bag  of  cheese-cloth  upon  their  food-plant.  If  the  butterfly 
happens  to  be  in  just  the  right  condition,  eggs  will  be 
obtained;  otherwise,  not,  so  that  many  attempts  must  of  ten 
be  made  before  success  is  reached.  After  the  eggs  are 
obtained  the  rest  of  the  process  is  much  simpler.  No 
attention  need  be  given  to  the  eggs  until  the  young  cater- 
pillars are  hatched,  or  are  about  to  hatch,  when  they  should 
be  taken  indoors  and  provided  from  time  to  time  with  their 
proper  food.  It  is  generally  well  to  keep  them  enclosed,  so 
that  they  will  not  escape.  For  a  few  caterpillars  use  a 
lamp  chimney  or  lantern  globe  set  upon  a  flower-pot,  within 
which  a  twig  of  the  food  is  inserted  in  moist  sand ;  over  the 
top  may  be  tied  a  piece  of  cheese-cloth  to  prevent  the  escape 
of  the  worms.  In  this  way  the  food  may  be  kept  fresh  for 
several  days.  It  is  a  good  thing  to  keep  the  breeding  cage 
clean  by  removing  all  droppings,  or  better  still,  to  make  a 
new  cage  at  each  change  of  food.  It  is  well  also  to  have 
as  few  larvae  as  convenient  in  each  cage.  After  the  larva? 
are  full  grown  and  have  pupated,  the  pupas  should  be  kept 
in  a  dry  situation,  but  occasionally  sprinkled  with  water, 
so  that  they  will  not  dry  out  too  much  until  they  are  ready 
to  hatch.  It  is  well  to  keep  each  by  itself  in  a  pasteboard 
box  of  sufficient  size  to  enable  the  butterfly,  as  it  emerges, 
to  have  ample  room  for  spreading  its  wings;  but  they  must 
be  looked  after  very  regularly,  so  as  to  remove  them  as 
soon  as  the  wings  are  firm.  It  takes  about  two  days  after 
emergence  before  the  wings  have  obtained  their  full  hard- 
ness and  the  insects  are  ready  to  be  killed  and  spread  for 
the  collection. 

LIST  OF  THE  BUTTERFLIES  OF  CALIFORNIA. 

The  classification   or  naming  of  insects  is  of  but  little 
value  in  itself;    but  as  a  means  of  recording  accurately 


30 

one's  observations  on  the  development  of  group  forms,  or 
of  such  observations  as  are  suggested  in  this  Bulletin,  it 
becomes  of  the  highest  importance.  The  following  list  and 
the  illustrations  accompanying  it,  are  designed  to  aid  the 
student  in  at  least  approximately  placing  his  specimens. 
The  two  plates  of  photographs  give  pictures  of  forty  of 
the  commoner  species,  so  that  most  of  the  kinds  likely  to 
be  observed  by  the  students  can  be  immediately  located. 
At  the  beginning  of  each  family  are  also  given  sketches 
showing  the  venation  of  the  wings  of  most  of  the  genera, 
and  to  these  reference  is  made  by  the  numbers  outside  of 
parentheses.  In  doubtful  cases  these  will  be  found  useful. 
The  list  proper  (numbered  consecutively  within  paren- 
theses) contains  the  names  of  all  the  butterflies  found  in 
the  State;  so  as  surely  to  include  all  that  occur  here,  those 
recorded  from  adjoining  States  are  also  given,  but  in  every 
case  that  fact  is  noted.  Thus,  the  word  "Arizona,"  fol- 
lowing a  species  name,  indicates  that  the  species  has  not 
yet  been  recorded  from  California,  but  might  be  looked  for 
along  the  south-eastern  border  of  the  State.  Notes  as  to 
abundance,  food  habits,  and  distribution,  follow  the  more 
important  species. 

FAMILY    NYMPH ALID.E. 

This  family  is  characterized  by  the  functionless  front 
legs,  (see  Fig.  2)  and  is  considered  the  highest-developed 
of  the  series.  The  species  are  mostly  of  large  size  and  vary 
greatly  in  appearance. 

Sub-family  EUPLOEINAE. 

Anosia.  1.  (1)  A.  plexippus,  Linn.  (Plate  1).  Occurs  all  over  the 
State;  flies  all  the  year;  larva  feeds  on  milkweed.  Perhaps  the 
most  useful  butterfly  for  study.  (2)  A.  berenice  Cram.,  Arizona 
and  southern  California.  (3)  A.  strigosa,  Bates,  Arizona. 

Sub-family  ITHOMIINAE. 

Mechanitis.    2.    (4)   M.    californica,    Reak.,    (5)  M.    utemasia,   Beak. 
Dynothea.  3.  (6)  D.  lyeaste,  Pabr.     The  species  of  this  family  are  all 
rare  and  confined  to  the  southern  part  of  the  State. 


Sub-family  NYMPHALINAE. 

Agrawlis.  4.  (7)  A.  vanillse,  Linn.  (Plate  1).  Very  abundant  in 
the  south.  Larva  feeds  on  passion  vine. 

Euptoieta.  5.  (8)  E.  claudia,  Cram.  (9)  E.  hegesia,  Cram.  Two 
rarer  passion -vine  butterflies,  also  belonging  to  the  south. 

Argynnis  6.  (10)  A.  nokomis,  Edw.  (Plate  l.j  This  species  and  the 
two  following  are  yellowish  instead  of  reddish -brown  in  the  female, 
as  is  the  rule  in  the  genus.  The  female  is  figured.  (11)  A.  nito- 
cris,  Edw.,  Arizona,  Nevada.  (12)  A.  leto,  Behr.  A  common  form 
in  the  Yosemite  valley.  (13)  A.  cybele,  Fabr.,  Arizona.  (14)  A. 
aphrodite,  Fabr.,  Arizona.  (15)  A.  cipris,  Edw.,  (16)  A.  nausicaa, 


Plate  3. 


32 

Edw.,  Arizona.  (17)  A.  hippolyta,  Edw.,  (18)  A.  brernneri,  Edw. 
These  last  two  are  rather  northern  forms.  (19)  A.  zerene,  Bdv. 
(20)  A.  monticola,  Behr.  These  last  two  are  common  in  the  Yosemite 
region  and  of  rather  wide  distribution  elsewhere.  (21)  A.  behren- 
si,  Edw.  Another  northern  form.  (22)  A.  halcyone,  Edw. , 
Arizona.  (23)  A.  oweni,  Edw.,  (24)  A.  chitone,  Edw.,  (25)  A. 
semiramis,  Edw.,  (26)  A.  coronis,  Behr.  (27)  A.  callippe,  Bdv. 
(28)  A.  nevadensis,  Edw.,  (29)  A.  edwardsi,  Edw.,  (30)  A.  liliana, 
H.  Edw.,  (31)  A.  montivaga,  Behr.  (32)  A.  egleis,  Bdv. 

The  above  rather  formidable  list  is  made  up  mostly  of 
somewhat  rare  butterflies.  The  species  of  this  genus  are 
almost  exclusively  confined  to  the  eastern  edge  of  the  State. 
The  differences  between  many  of  the  forms  are  so  slight 
that  they  are  difficult  to  distinguish,  and  the  species  are 
doubtfully  distinct.  To  ascertain  how  many  are  really  good 
species,  we  wish  especially  to  receive  many  specimens  of 
every  kind,  with  data  about  their  rather  peculiar  distribu- 
tion. No  butterflies  are  better  for  the  study  of  the  variation 
of  wing  pattern. 

Brenthis.  7.  (33)  B.  myrina,  Cram.  An  Eastern  species  rather 
doubtfully  credited  to  this  State.  (34)  B.  helena,  Edw.,  Arizona. 
(35)  B.  bellona,  Pabr.,  (36)  B.  epithore.,  Bdv.  The  last  two  species 
are  not  uncommon  and  are  found  in  the  same  situations  as  the 
members  of  the  preceding  genus,  with  which  this  genus  is  often 
united.  B.  morrisoni,  Beak.,  and  B.  nenoquis,  Beak.,  were 
described  as  coming  from  California,  but  probably  by  mistake. 

Melitaea.  8.  (37)  M.  cooperi,  Behr.  (38)  M.  chalcedon,  Doub.  &  Hew. 
(Plate  1).  One  of  the  commoner  species.  (39)  M.  macglashani, 
Rivers.  (40)  M.  augusta,  Edw.  (41)  M.  colon,  Edw.,  Oregon. 
(42)  M.  anicia,  Doub.  &  Hew.  (43)  M.  nubigena,  Behr.  (44)  M. 
quino,  Behr.  (45)  M.  baroni,  H.  Edw.  (46)  M.  editha,  Behr.  (47) 
M.  rubicunda,  H.  Edw.  (48)  M.  sterope,  Edw.,  Oregon.  (49)  M. 
acastus,  Edw.,  Nevada.  (50)  M.  palla,  Bdv.  (51)  M.  whitneyi, 
Behr.  (52)  M.  hoffmani,  Behr.,  (53)  M.  gabi,  Behr.  These 
insects  deserve  careful  study.  The  group  is  distinctly  Calif ornian. 
Their  distribution  is  very  peculiar,  and  the  distinctness  of  the 
species  somewhat  doubtful.  The  larvse  feed  on  a  great  variety  of 
plants,  but  chiefly  Scrophulariaceae  (Fig-wort  family). 

Thesalia.  (54)  T.  perse,  Edw.,  Arizona.  (55)  T.  elada,  Doub.  & 
Hew.,  Arizona.  (56)  T.  chara,  Edw.,  Arizona.  (57)  T.  leanira, 
Bdv.  A  rather  common  and  widely  distributed  species.  (58)  T. 
alma,  Strk.,  Arizona.  (59)  T.  wrighti,  Edw.  (60)  T.  thekla, 


33 

Edw.  (61)  T.  bolli,  Edw.,  Arizona.  (62)  T.  minuta,  Edw., 
Arizona.  (63)  T.  arachne,  Edw.,  Arizona.  (64)  T.  nympha, 
Edw.,  Arizona. 

The  above  group  is  generally  united  with  the  preceding 
genus,  but  seems  to  be  a  distinct  group.  Many  of  the 
species  are  doubtfully  distinct.  Nothing  is  known  of  the 
food  habits. 

Charidryas.     (65)  C.  nycteis,  Doub.  and  Hew.      Widely  distributed; 

larva  feeds  on  Composites  (Composite  family) .  (66)  C.  carlota,. Reak. 

This  genus  is  generally  associated  with  the  next. 
Phyciodes.    9.     (67)  P.  tharos,  Dru.     Widely  distributed,  larva  feeds 

on  Aetinomeris  and  probably  Composite  generally.  (68)  P.  pratensis, 

Behr.    (Plate  1).   A  common  species  (69)  P.  orseis,  Edw.    (70)  P. 

mylitta,  Edw.    A  common  species.    (71)  P.  montana,  Behr.    (72)  P. 

picta,  Edw.  (73)  P.  hermas,  Hew. 
Eresia.    10.    (74)  E.  punctata,  Edw. 
Chlosyne.    11.    (75)  C.  crocale,  Edw. 
Polygonia.    12.    (76)  P.  interrogationis,  Fabr.     (77)  P.  satyrus,  Edw. 

(Plate  1).    (78)  P.  rusticus,  Edw.    (79)  P.  faunus,  Edw.    (80)  P. 

sylvius,  Edw.    (81)  P.  zephyrus,  Edw.    (82)    P.  silenus,  Edw.     A 

group  of  very  characteristically  marked  insects ;   very  uniform  in 

pattern  and  habits.     The  larvae  feed  on  nettles  and  allied  plants. 
Euvanessa.    13.    (83)  E.  antiopa,  Linn.     (Plate  1).     A  very  common 

butterfly,   and  one  of  the  most  available  for  breeding,   since  the 

larvae  are  social,  feeding  on  elm  and  willow. 
Eugonia.    (84)  E.  californica,  Bdv.    (Plate  1).    Closely  allied  to  the 

preceding  genus,  but  with  much  the  appearance  of  Polygonia. 
Aglais.  (85)  A.  milberti,  Godt.  (Plate  1).  Allied  to  Euvanessa. 
Vanessa.  14.  (86)  V.  atlanta,  Linn.  (Plate  1).  (87)  V.  huntera, 

Fabr.      (88)  V.   cardui,    Linn.      (89)   V.   caryse,  Hubn.      (Fig.    3). 

This  species  is  the  commoner  form,  like  the  other  species  of  the 

genus;  the  larva  feeds  on  a  variety  of  plants,  including  nettles. 
Junonia.     15.     (90)   J.   coenia,    Hubn.       (Plate   1).      A  very  common 

species.     (91)  J.  genoveva,  Cram.     (92)  J.  lavinia,  Gram. 
Basilarchia.  16.   (93)  B.  astyanax,  Fabr.    (94)  B.  arthemis,  Dru.    (95) 

B.  weidemeyeri,  Edw.     (96)   B.  disippus,   Godt.     (97)  B.  lorquini, 

Bdv.    (98)  B.  hulsti,  Edw.,  Arizona.     These  insects  feed  on  a  great 

variety  of  trees  and  shrubs. 
Adelpha.     17.     (99)    A.    californica,    Butl.      (Plate    1).      A  common 

butterfly;  the  larva  feeds  on  oak. 
Chlorippe.    18.    (100)  C.  celtis,  Bdv.  and  Lee.     (101)  C.  antonia,  Edw. 

(102)  C.  leilia,  Edw.     None  of  these  insects  are  common. 
Pyrrhancea.    19.    (103)  P.  morrisoni,  Edw.,  Arizona. 


34 


Sub -family  SATYRINAE. 

Neonympha.    20.    (104)  N.  henshawi,  Edw.    (105)  N.  rubricata,  Edw. 
Ccenonympha.     21.     (106)    C.    California,    Westw.      (Plate    1).     Very 

common  towards  fall.     (107)   C.  inornata,  Edw.     (108)  C.  pamphil- 

oides,  Reak. 

Gyrocheilus.    22.    (109)  G.  tritonia,  Edw.,  Arizona. 
Neominois.    23.    (110)  N.  ridingsi,  Edw. 
Cereyonis.    24.    (Ill)  C.  wheeleri,  Edw.     (112)  C.  meadi,  Edw.    (113) 

C.   sthenele,    Bdv.     (114)    C.   baroni,    Edw.     (115)    C.    silvestHs, 

Edw.     (116)    C.  ostus,  Bdv. 
CEneis.    25.    (117)  O.   nevadensis,  Feld.     (118)    O.    californica,    Bdv. 

(119)    O.  iduna,  Edw.    (120)  F.  chryxus,  Westw.    (121)  O.  ivallda, 

Mead. 

Sub -family  LIBYTHEINAE. 

Libytliea.  26.   (122)  L.  bachrnanii,  Kirtl.     (123)  L.  carinenta,  Cram. 


FAMILY  LYCAENID.E. 

This  family  consists  entirely  of  small  delicate  butterflies 
usually  of  a  blue  or  copper  color.  They  can  be  distin- 
guished by  the  narrowness  of  the  face  between  the  eyes. 


Plate  4. 

Sub -family  ERYCININ^E. 

Chrysobia.   27.  (124)  C.  mormo,  Feld.  (125)  C.  cythera,  Edw.,  Arizona. 
(126)  C.  virgulti,  Behr.  (Plate  1).    (127)    C.    nais,    Edw.    Arizona, 
(128)  C.  palmeri,  Edw.,  Arizona.     (129)  C.  zela,  Butl.,  Arizona. 
Calephelis.    28.   (130)  C.  nemesis,  Edw.  (131)  C.  australis,  Edw.    The 


insects  of  this  sub-family  all  belong  to  the  south, 
the  larva  is  unknown. 


In  most  cases 


35 


Sub-family 

Tribe  Thecline.    The  "  Hair  streaks." 
Habrodius.     (132)  H.  grunus,  Bdv. 
Atlides.     (133)  A.  halesus,  Cram.     These    two    genera    are    generally 

united  with  the  following  with  which  they  are  closely  allied.     The 

larvae  feed  upon  oak. 
Thecla.    29.    (134)  T.  sylvinus,  Bdv.     (135)    T.    itys,    Edw.,  Arizona. 

(136)  T.  auretorum,  Bdv.    (137)  T.  dryope,  Edw.     (138)  T.  spadix, 

H.  Edw.  (139)  T.  tetra,  Behr.  (140)   T.    chalcis,    Behr.    (141)    T. 

sfepium,  Bdv.   (142)  T.  nelsoni,  Bdv.  (143)  T.  adenostomatis,    H. 

Edw.  (144)  T.  tacita,  H.  Edw.   (145)  T.   spinetorum,    Bdv.    (146) 

T.  blenina,  Hew.     The   early  stages  of  all    our    species    are    un- 

known. 
Uranotes.   30.    (147)  U.  melinus,  Hubn.     (Plate  1).     This    is    one    of 

the  hop  butterflies  and  very  widely  distributed.     (148)  U.  alcestis, 

Edw.,  Arizona. 
Metura.  31.    (149)  M.  acis,  Edw.   (150)  M.  leda,  Edw.,  Arizona,  (151) 

M.  ines,  Edw.,  Arizona.     The   early  stages    of   these    species  are 

unknown. 
Callypsyclie.    (152)    C.  behri,  Edw.     A    northern    species    whose   life 

history  is  unknown. 
Incisalia.   32.  (153)  I.  augusta,  Kirby.  (154)  I.  iroides,  Bdv.  (155)  I. 

fotis,  Strk.,  Arizona.     (156)  I.  eryphon,  Bdv.     The  life  history  of 

none  of  these  is  known. 

Callophrys,  (157)  C.  dumetorum,  Bdv.  (158)  C.  apama,  Edw. 
Erora.    (159)  E.  leeta,  Edw.,  Arizona. 
Strymon.    33.  (160)  S.    titus,  Fabr.,  Arizona.    Larva    feeds    on    wild 

cherry  and  plum. 

Tribe  Chrysophanini.    The  "Coppers." 
Tharsalea.  (161)  T.  arota,  Bdv.  The  larva  feeds  on  wild  gooseberry. 

(162)  T.  virginiensis,  Edw.  (163)  T.  hermes,  Edw. 
Gceides.    34.    (164)  G.   xanthoides,    Bdv.    (Plate  1).     (165)  G.  editha, 

Mead,  Nevada.     (166)  G.  gorgon,    Bdv.     The    larvse  of   these    are 

unknown. 
Epidemia.    (167)  E.  mariposa,  Eeak.    (168)  E.  zeroe,   Bdv.    (169)    E. 

helloides,  Bdv.     The  larva?  of  these  are  also  unknown. 
Helodes.    (170)  H.  hypophlaeas,  Bdv.  (Plate  1). 

Tribe  Lycaenini    The  "  Blues." 
Satrium.    (171)  S.  fuliginosum,  Edw. 
Cupido.    (172)  C.  heteronea,  Bdv.   (173)  C.  clara,   H.   Edw.    (174)   C. 

lycea,  Edw.,  Arizona.   (175)  C.  fulla,  Edw.    (176)  C.  ssepiolus,  Bdv. 

(177)  C.  dsedalus,  Behr.   (178)  C.  icarioides,  Bdv.  (179)  C.  pheres. 

Bdv.  (180)  C.  phileros,  Bdv.  (181)  C.  ardea,  Edw. 


36 

Nomiades.   (182)  N.  xerxes,    Bdv.    (183)    N.    antiacis,  Bdv.    (184)    N. 

lygdamas,  Doub. 

Phaddrotes.  (185)  P.  sagittigera,  Feld. 

Philotes.    (186)  P.  speciosa,  Edw.     (187)  P.  sonorensis,  Feld. 
Agriades.    (188)  A.  podarce,  Feld. 
Rusticus.    (189)  E.  enoptes,  Bdv.  (190)  E.  glaucon,  Edw.,  Nevada.  (191) 

E.  battoides,  Behr.  (192)  E.  shasta,  Edw.  (193)  E.  rnelissa,  Edw., 

Nevada,  Arizona.    (194)  E.  scudderi,  Edw.  Larva  feeds  on  lupines. 

(195)  E.  lotus,  Lint.  (196)  E.  acmon,  Edw.     (197)  E.  anna,    Edw. 

(Plate  1). 
Cyaniris.    35.    (198)  C.  pseudargiolus,  Bdv.  &  Lee.     Larvse  feed  on  a 

great  variety  of  plants. 
Everes.    36.    (199)  E.  tejua,  Eeak.     (200)  E.  ainyntula,  Bdv.     (201)  E. 

comyntas,    Gdt.,    Arizona.      Larva    feeds    on    leguminous    plants. 

(202)  E.  monica,  Eeak. 

Hemiargus.    (203)   H.  isola,  Eeak.      (204)  H.  gyas,  Edw.,  Arizona. 
Brephidium.    (205)    B.  exile,  Bdv.     (Plate  1). 
Leptotes.    (206)    L.  marina,  Eeak. 

The  life  history  of  these  insects,  except  in  the  few  cases 
noted  above,  is  still  known. 

FAMILY  PAPILIONID^:. 

This  family  includes  two  distinct  types  of  butterflies, 
representing  the  two  sub-families. 


Plate  5. 


PLATE  1. 


PLATE  2, 


Sub -family  PIERIN.E. 
Tribe  Pierini.    The  "Whites." 

Neophasia.  37.  (207)  N.  menapia,  Feld.  (Plate  2).  This  is  a  northern 
species;  the  larva  feeds  on  pine  and  fir. 

Pontia.  (208)  P.  beckeri,  Edw.  (209)  P.  sisymbri,  Bdv.  (210)  P. 
occidentalis,  Reak.  (211)  P.  protodice,  Bdv.  and  Lee.  (Plate  2). 
The  last  species  is  very  abundant ;  the  larva  feeds  on  cabbage  and 
other  Cruciferee  (mustard  family),  as  do  the  other  species  of  the 
genus.  This  genus  is  generally  united  with  the  Pieris. 

Pierls.  38.  (212)  P.  napi,  Esp.  Larva  feeds  on  mustard.  (213)  P. 
rapae,  Linn.  (Plate  2).  The  commonest  and  most  injurious  insect 
of  the'family  and  perhaps  of  all  butterflies.  The  larva  feeds  on 
cabbage.  Is  a  very  useful  insect  for  study. 

Nathalis.  39.  (214)  N.  iole,  Bdv.  (Plate  2).  This  insect  is  found 
in  the  southern  part  of  the  State. 

Midea.    (215)  M.  lanceolata,  Bdv.     The  larva  feeds  on  Turritis. 

SyncMoe.  (216)  S.  creusa,  Doub.  &  Hew.  (Plate  2).  (217)  S.  auso- 
nides,  Edw.  These  feed  on  Cruciferae  (mustard  family). 

Anthocharis.  40.  (218)  A.  latta.  (219)  A.  sara,  Bdv.  (Plate  2).  (220) 
A.  cethura,  Field.  (221)  A.  pima,  Edw.,  Arizona.  These  feed, 
as  far  as  known,  on  Cruciferae  (mustard  family) .  The  three  pre- 
ceding genera  are  sometimes  grouped  as  one,  either  under  the 
name  Anthocharis  or  Euchloe. 

Tribe  Coliini.    The  "Yellows." 

Callidryas.  41.  (222)  C.  eubule,  Linn.  (223)  C.  philea,  Linn., 
Arizona.  The  larvae  of  these  feed  on  leguminous  plants. 

Zerene.  42.  (224)  Z.  eurydice,  Bdv.  (Plate  2).  The  larva  feeds  on 
Amorpha  californica  (Californian  false  indigo).  (225)  Z.  csesonia, 
Stoll. 

Eurymus.  43.  (226)  E.  eury theme,  Bdv.  (227)  E.  philodice,  Gdt. 
(228)  E.  harfordi,  H.  Edw.  (229)  E.  occidentalis,  Scud.  (230) 
E.  Christiana,  Edw.,  Oregon.  (231)  F.  alexandra,  Edw.,  Nevada, 
Oregon.  (232)  E.  emilia,  Edw.  (233)  E.  interior,  Scud.  (234) 
E.  behri,  Edw.  These  insects  vary  greatly,  and  the  differences 
between  the  species  are  so  small  that  it  seems  doubtful  that  they 
are  really  distinct.  The  larvae  feed  on  a  variety  of  plants  of  the 
Leguminosae  (pulse  family),  especially  clover  and  alfalfa. 

Xantliidia.  44.  (235)  X.  gundlachia,  Poey,  Arizona.  (236)  X.  pro- 
terpia,  Fabr.,  Arizona.  (237)  X.  nicippe,  Cram.,  Arizona.  Larva 
feeds  on  Cassia.  (238)  X.  mexicana,  Bdv.  (239)  X.  damaris, 
Feld.,  Arizona.  Southern  forms.  This  and  the  next  genus  are 
generally  united  under  the  name  Terias. 

Eurema.    (240)  E.  lisa,  Bdv.  &  Lee.     The  larva  feeds  on  Cassia. 


Sub-family  PAPILIONIN.E. 
Tribe  Parnassiini.    The  "Parnassians." 

Parnassius.    45.    (241)    P.  nomion,    Fiseh.       (242)    P.    elodius,    Men 
(243)  P.  smintheus,  Db.  &  Hew.    (Plate  2).      The  larvse  of  these 
delicate  southern  butterflies  feed  on  Sedum  (stone  crop)  and  Saxi- 
frage. 

Tribe  Papilionini.    The  "  Swallow-tails." 

Jasoniades.  (244)  J.  eurymedon,  Bdv.  The  larva  feeds  on  Rhamnus 
and  various  other  plants.  (245)  J.  rutulus,  Bdv.  (Plate  2).  The 
larva  of  this  common  species  feeds  on  alder  and  willow.  (246)  J. 
daunus,  Bdv.  The  larva  feeds  on  various  species  of  s  the  rose 
family.  (247)  J.  pilumnus,  Bdv.  The  larva  feeds  on  laurel. 

Papilio.  46.  (248)  P.  asterias,  Fabr.  (249)  P.  bairdi,  Edw.,  Ari- 
zona. (250)  P.  indra,  Eeak.  (251)  P.  pergamus,  H.  Edw.  (252) 
P.  hollandi,  Edw.,  Arizona.  (253)  P.  machaon,  Linn.  (254)  P. 
oregonia,  Edw.,  Oregon,  Arizona.  (255)  P.  zolicaon,  Bdv.  (256) 
P.  americus,  Koll.  These  all  feed  as  larvae  on  various  Umbelli- 
ferse  (parsley  family).  There  is  much  room  for  doubt  whether  all 
the  species  are  distinct,  but  there  are  three  quite  distinct  groups 
containing  respectively  two,  three,  and  four  of  this  species. 

Euphloedes.  (257)  E.  troilus,  Linn.  Very  doubtfully  credited  to  this 
State.  The  larva  feeds  on  spicewood  and  sassafras. 

Laertias.  (258)  L.  philenor,  Linn.  (259)  L.  mylotes,  Bates.  The 
larva  feeds  on  Aristolochia  (Dutchman's  pipe). 

Heriaclides.  (260)  H.  thoas,  Linn.,  Arizona.  The  larva  feeds  on 
citrus  trees. 

FAMILY  HESPERID.E. 

This  family  of  heavy  bodied  butterflies  known  as  "  skip- 
pers" can  be  distinguished  by  their  very  wide  heads  and 
the  insertion  of  the  antennae  far  apart.  They  are  con- 
sidered the  lowest  family,  and  the  one  that  approaches 
nearest  to  the  moths. 

These  insects  need  more  study  along  every  line.  The 
generic  placing  of  some  of  the  species  given  below  is  rather 
doubtful. 

Sub -family  PYRRHOPYGIN^E. 
Pyrrhopyge.    47.    (261)    P.  araxis,  Hew.,  Arizona. 

Sub-family  HESPERIIN.E. 

Eudamus.     48.    (262)    F.  simplicius,    Stall.     (263)     F.    albofasciatus, 

Hew. 
Plestia.    49.    (264)    P.  dorus,  Edw.,  Arizona. 


39 

Epargyreus.  50.  (265)  F.  tityrus,  Fabr.  (Plate  2).  The  larva  lives 
in  a  nest  and  feeds  on  various  leguminous  plants. 

Thorybes.  51.  (266)  T.  pylades,  Scud.  The  larva  feeds  on  Lespe- 
deza(bush  clover)  and  Desmodium  (tick  trefoil).  (267)  T.  nevadae, 
Scud.,  Nevada.  (268)  T.  bathyllus,  Sm.  &  Abb.  (Plate  2).  Larva 
feeds  on  a  variety  of  leguminous  plants.  (269)  T.  moschus,  Edw., 
Arizona.  (270)  T.  hippalus,  Edw.,  Arizona.  (271)  T.  drusius, 
Edw.,  Arizona.  (272)  T.  epigena,  Edw.,  Arizona. 


Plate  6. 

Achalarus.    52.    (273)    A.    cellus,    Bdv.    &  Lee.      The  larva  feeds  on 

Desmodium  (tick-trefoil). 
Hesperia.    53.    (274)  H.  ericetorum,    Bdv.     (275)  H.  oceanus,  Edw., 

Arizona.     (276)    H.  domicella,  Erich,    Arizona.     (277)    H.  tessel- 

lata,   Scud.     Very  common.     (278)    H.  caespitalis,  Bdv.     (279)  H. 

scriptura,  Bdv.     The  larvae  of  all  these   are   supposed  to  feed  on 

various  Malvaceae  (mallow  family) . 
Systasea.    54.    (280)    S.  zampa,  Edw.,  Arizona. 
Pliolisora.    55.    (281)    P.  catullus,  Fabr.     The  larvae  feed  on  Chena- 

podium.     (282)    P.  pirus,  Edw.,    Arizona.     (283)    P.    ceos,    Edw., 

Arizona.     (284)    P.  libya,  Scud. 
Tlmnaos.    56.    (285)    T.  brizo,   Bdv.    &  Lee.     (286)    T.  icelus,   Lint. 

The  larvae  of  these  two  feed  on  oaks.      (287)    T.   persius,    Scud. 

(Plate  2).     The  larva  feeds  on  willow.     (288)    T.    afranius,  Lint., 

Arizona.     (289)    T.  juvenalis,  Fabr.,  Arizona.     The  larva  feeds  on 

oak  and  also   on  leguminous   plants.     (290)    T.   propertius,   Lint. 

(291)     T.    pacuvius,     Lint.,     Arizona.       (292)     T.    tatius,     Edw., 


40 

Arizona.     (293)    T.    clitus,    Edw.,    Arizona.      (294)    T.  funeralis, 
Lint.     (295)    T.  tristis,  Bdv.     (296)    T.  tibullus,  Scud-Burg. 

Sub -family  PAMPHILINJE. 

AmUyscirtes.  57.  (297)  A.  amus,  Edw.  (298)  A.  simius,  Edw. 
(299)  A.  cassus,  Edw.  (300)  A.  nanno,  Edw.  These  four  species 
are  Arizonian,  and  nothing  is  known  of  their  life  histories. 

PampMlia.  58.  (301)  P.  mandan,  Edw.  (302)  P.  oinaha,  Edw. 
The  larvse  of  these  feed  on  grasses. 

Oarisma.    59.    (303)    O.  garita,  Reak,  Arizona. 

Ancyloxypha.  60.  (304)  A.  numitor,  Fabr.  The  larvse  live  in  nests 
on  marsh  grasses. 

Copceodes.  61.  (305)  C.  procris,  Edw.  (306)  C.  arene,  Edw., 
Arizona.  (307)  C.  wrighti,  Edw.  (308)  C.  myrtis,  Edw.,  Arizona. 
(309)  C.  eunus,  Edw. 

Erynnis.  62.  (310)  E.  taxiles,  Edw.  (311)  E.  ruricola,  Bdv.  (312) 
E.  oregonia,  Edw.  (313)  E.  Columbia.  Scud.  (314)  E.  nevada, 
Scud.,  Nevada,  Arizona.  (315)  E.  manitoba,  Scud.  (316)  E. 
juba,  Scud.  (317)  E.  harpalus,  Edw.,  Nevada.  (318)  E.  ottoe, 
Edw.,  Arizona.  (319)  E.  lasus,  Edw.,  Arizona.  (320)  E.  cabe- 
lus,  Edw.  (321)  E.  rhusus,  Edw.,  Arizona.  (322)  E.  carus, 
Edw.,  Arizona.  (323)  E.  uncas,  Edw.,  Arizona.  (324)  E.  yuma, 
Edw.,  Arizona.  (325)  E.  snowi,  Edw.,  Arizona.  The  life-his- 
tory of  none  of  these  is  known. 

OcUodes.  63.  (326)  O.  nemorum,  Bdv.  (327)  O.  sylvanoides,  Bdv. 
(328)  O.  agricola,  Bdv.  (329)  O.  milo,  Edw.,  Oregon.  (330)  O. 
pratincola,  Bdv.  (331)  O.  verus.  The  life-history  of  none  of 
these  is  known. 

Atalopedes.  64.  (332)  A.  campestris,  Bdv.  (Plate  2).  A  very  com- 
mon species. 

Polites.  65.  (333)  P.  sabuleti,  Edw.  (334)  P.  mardon,  Edw., 
Oregon. 

Hylephila.  66.  (335)  H.  phylseus,  Drury.  (336)  S.  chusca,  Edw. 
Arizona.  The  larvse  feed  on  grass. 

Calpodes.  67.  (337)  C.  pittacus,  Edw.  (338)  C.  python,  Edw.  (339) 
C.  cestus,  Edw.  All  Arizonian. 

Lerodea.  68.  (340)  L.  comus,  Edw.  (341)  L.  arabus,  Edw.,  Arizona. 
(342)  L.  nereus,  Edw.,  Arizona. 

Limochores.  69  (343)  L.  cernes,  Edw.  (344)  L.  manataaqua,  Scud. 
The  larvse  live  in  tube -like  nests  on  grass. 

Euphyes.  70.  (345)  E.  verna,  Edw.  (Plate  2).  Larvae  feed  on 
grass.  (346)  E.  vestris,  Bdv.  (347)  E.  metacomet,  Harr.,  Nevada. 
(348)  E.  bella,  Edw.,  Arizona. 

Oligoria.  71.  (349)  O.  deva,  Edw.,  Arizona.  (350)  O.  lunus,  Edw., 
Arizona. 

Atrytone.  72.  (351)  A.  melaiie,  Edw.  (352)  A.  taxiles,  Edw., 
Nevada,  Arizona. 

Megathymus.  (353)  M.  yuccea,  Bdv.  &  Lee.,  Arizona.  (354)  M. 
neumoegenii,  Edw.,  Arizona. 


THE  LIVING  PLANT. 


By  W.  J.  V.    OSTERHOUT, 
Instructor  in  Botany. 


TABLE  OF  CONTENTS. 


The  Study  of  the  Living  Plant. 
The  Seed. 

Awakening  of  the  Plant. 
Getting  out  of  the  Seed -covering. 
•  Getting  into  the  Ground. 

Seed  Leaves  and  Foliage  Leaves,  and  their  Work. 
Work  of  the  Root. 
How  Roots  and  Stems  Grow. 
Why  the  Root  Grows  Downward. 
Do  Roots  Seek  Water? 
Do  Stems  Seek  Light? 
Do  Leaves  Seek  Light? 


THE  STUDY  OF  THE  LIVING  PLANT. 


It  seems  to  be  generally  admitted  that  plants  are 
especially  suitable  objects  for  nature  study,  but  it  is  to 
be  regretted  that  too  often  the  attention  is  centered  on 
the  dead  plant  to  the  exclusion  of  the  living  one.  This 
is  a  mistake,  and  will  be  recognized  as  such  if  the  aims 
of  nature  study  are  not  lost  sight  of.  These  are,  first,  to 
put  the  child  in  the  right  attitude,  to  awaken  his  sym- 
pathetic interest  in  plant-life;  and,  second,  to  develop  his 
observing  and  reasoning  powers  in  leading  him  to  find 
out  for  himself  what  the  plant  is  doing  and  why  it  does  it. 
Both  these  objects  may  be  admirably  attained  by  experiments 
performed  by  the  children  themselves,  on  living  plants. 

Experiments  should  not  be  performed  in  a  haphazard 
manner,  nor — as  usually  happens — to  demonstrate  some- 
thing the  child  has  already  accepted  as  a  fact;  but  to  answer 
questions  which  have  been  previously  put  by  the  child 
himself,  or  by  the  teacher.  I  believe  this  point  to  be  of 
fundamental  importance,  although  generally  overlooked. 
Experiments  seem  to  be  usually  regarded  as  useful  for 
demonstrative  purposes  only.  I  do  not  believe  that  for 
nature  study  at  least,  this  is  the  best  use  to  which  they  can 
be  put.  The  child  can  use  experiments  for  the  same 
purpose  as  the  investigator  uses  them,  i.e.,  for  putting 
questions  to  nature,  and  will  find  in  this  a  mental 


44 

quickening  and  zest  such  as  comes  in  no  other  way. 
Children  are  investigators,  in  their  own  way,  and  enjoy 
experiments  of  all  kinds,  especially  experiments  with  things 
which  are  alive. 

An  enthusiastic  and  sympathetic  teacher  will  easily  get 
the  children  to  ask  questions;  the  next  step  is  to  show 
them  how  to  answer  their  own  questions  by  experiments, 
or,  better  still,  lead  them  to  suggest  for  themselves  how  to 
do  this.  Herein  lies  the  value  of  the  method.  It  leads  the 
child  to  think;  reveals  to  him  his  own  power  to  find  out 
things,  and  creates  an  interest  which  does  not  die  when 
he  leaves  the  schoolroom.  He  gains,  almost  without 
conscious  effort,  an  insight  into  plant-life  which  makes 
plants  attractive  and  interesting  wherever  he  sees  them,  and 
which  will  surely  entice  him  into  the  fields.  He  comes  to  see 
the  plant  in  a  new  and  wonderfully  inspiring  way,  as  a 
living,  struggling  being,  attacking  its  competitors,  warding 
off  its  foes,  adapting  itself  by  clever  devices  to  harsh  and 
unfavorable  surroundings;  in  short,  solving  the  thousand 
and-one  problems  of  its  existence  with  consummate  skill. 
And  what  he  before  passed  over  with  apathy  he  will  learn 
to  observe,  admire,  and  study;  in  some  measure  he  will  come 
to  see  the  beauty  and  learn  the  lessons  of  common  things. 

Many  teachers  may  approve  of  experiments,  but  shrink 
from  what  they  suppose  requires  too  much  time  and  the  use 
of  complicated  apparatus.  I  wish  to  point  out  that  the  most 
interesting  and  instructive  experiments  can  be  performed 
either  with  110  apparatus  at  all  or  with  such  as  the  children 
can  easily  make  for  themselves ;  and  that  the  outlay  of  time 
and  money  are  exceedingly  small,  while  the  returns  are  of 
great  and  lasting  value. 

The  experiments  here  described  require  no  special  skill 
and  almost  no  apparatus.  The  few  articles  required  will 
also  serve  for  many  other  experiments.  The  necessary 
plants  can  all  be  grown  on  a  single  shelf  in  front  of  a 
convenient  window.  In  this  brief  space  I  can  mention 
only  a  few  experiments,  merely  enough  to  give  an  idea  of 


45 

the  method.  But  it  is  the  method  upon  which  I  desire  to 
lay  stress,  since  experiments  are  often  performed  in  such  a 
way  as  to  be  a  source  of  confusion  rather  than  of  inspiration. 

We  shall  do  well  to  begin  where  the  independent  life  of  The  Seed, 
the  plant  begins,  with  the  seed.  Plants  should  be  used 
which  are  familiar  to  everyone,  and  which  are  easily  grown 
and  cared  for.  Some  Scarlet  Runner  Beans  may  be  soaked 
over  night  and  given  the  children  to  examine,  together  with 
unsoaked  seeds  for  comparison.  How  does  soaking  affect 
the  covering  of  the  seed?  Do  all  seed-coverings*  behave 
in  this  way?  Try  some  hard,  resistant  ones,  such  as  the 
Castor  Bean,  Buckeye,  Acorn,  and  Peach  or  Cherry  pits. 
Of  what  use  is  the  seed-covering?  Does  it  help  the  taking 
up  of  water?  A  simple  way  to  answer  this  is  to  remove  it 
before  soaking  and  note  the  result  as  shown  by  the  general 
appearance  of  the  seed.  Acorns  are  good  for  this  purpose 
as  the  shells  are  easily  removed  and  the  seed  is  usually 
more  or  less  shrunken  and  becomes  plumper  on  taking  up 
water,  so  that  the  effect  can  be  easily  noted.  How  does  the 
water  get  through  the  seed-covering?  Select  some  well- 
soaked  Scarlet  Runner  Beans.  Wipe  them  perfectly  dry 
on  the  surface.  Now  squeeze  the  seed.  Does  water  ooze 
out?  Where?  Does  this  hole  in  the  seed-covering  allow 
water  to  enter?  Can  you  find  it  in  other  seeds?  Can  water 
get  into  the  seed  except  through  this  hole? — Take  some 
unsoaked  seeds.  Fasten  them  in  a  piece  of  split  cork  so 
that  when  it  floats  in  the  water  the  seeds  will  be  half 
submerged.  Let  the  hole  in  the  seed-covering  be  well 
above  the  water  and  take  care  to  keep  it  perfectly  dry.  If 
the  seed  takes  up  water  in  this  position  it  must  be  through 
the  seed-covering  itself.  It  is  interesting  to  use  seeds  with 
hard  coverings  for  this  experiment,  and  to  fasten  some  in 
the  reverse  position,  with  the  hole  under  water,  as  a  control- 
experiment. 

Within    the    seed-covering   is    a   tiny,    sleeping   plant. 

*  The  term  seed-covering  is  here  used  to  include  both  seed-coats  proper 
and  other  coverings  from  whatever  source  derived. 


46 

Notice  its  tiny  leaves,  radicle  and  seed-leaves  (Fig.  1). 
When  does  it  waken?  What  is  necessary 
to  make  it  germinate  and  grow?  Place 
some  soaked  seeds  in  damp  sawdust 
and  keep  one  lot  on  ice  and  another  in 
a  warm  place.  Place  some  unsoaked 
seeds  in  dry  sawdust,  and  keep  others 
immersed  in  water  which  has  been 
.FIG.  1.*  boiled  for  the  purpose  of  expelling 

the  air  and  then  allowed  to  cool.  On  the  top  of 
the  water  a  film  of  oil  may  be  placed  to  prevent  absorp- 
tion of  air.  Which  lot  of  seeds  germinates?  What 
prevents  the  others  from  doing  so?  Water,  air,  and  a 
certain  amount  of  heat  are  necessary  to  awaken  a  plant 
from  its  sleep.  How  long  will  plants  keep  alive  waiting 
for  a  chance  to  germinate?  Do  some  seeds  respond  more 
quickly  than  others  when  the  right  time  comes?  Is  this  an 
advantage  to  them?  When  a  plot  is  sown  for  a  lawn,  what 
plants  come  up  first,  the  grass  or  the  weeds?  Are  weeds 
apt  to  be  quick  starters?  Does  this  help  to  explain  their 
success  in  crowding  out  other  plants?  We  should  remem- 
ber that  there  is  a  constant  struggle  going  on  among  plants 
for  light,  because  if  a  plant  be  shaded  too  much  it  cannot 
live.  The  plants  also  crowd  each  other  and  struggle  for 
room  both  above  ground  and  below,  where  the  interlacing 
roots  are  eagerly  competing  for  the  nourishment  in  the  soil. 
Getting  out  of  When  the  awakened  seed  starts  to  grow,  it  must  first  get 
ou^  °^  ^s  imPrisoning  seed-covering.  When  the  covering 
is  tough  and  hard,  it  requires  considerable  exertion  to  get 
out.  Notice  how  the  seed  swells.  Does  it  exert  much 
force  on  the  seed-covering  in  swelling?  We  can  gain  some 
idea  of  this  if  we  put  as  many  seeds  as  we  can  into  a  thick- 
walled  bottle  and  immerse  it  in  water  over  night.  When 
morning  comes  the  bottle  will  be  found  in  fragments. 
Occasionally  a  ship,  laden  with  rice  or  grain,  founders  or 
runs  aground  where  the  waves  break  over  her,  and  the 
swelling  seeds  burst  her  in  pieces  just  as  they  do  the  bottle. 

*A11  drawings  were  made  from  nature  by  Mr.  A.  A.  Lawson. 


47 


FIG.  2A. 


FIG.  2B. 


In  the  Scarlet  Runner  where  do  we  find  the  first  rupture 
of  the  seed-covering?  Is  there  any  reason 
for  its  occurrence  in  this  particular  spot? 
Remember  that  the  radicle  and  the  hole  in 
the  seed- covering  are  both  found  here.  Is 
this  so  in  all  seeds?  Is  it  any  advantage  to 
the  radicle  to  double  itself  up  as  in  Fig. 
2 A?  Why?  Notice  how  it  behaves  as  soon 
as  it  is  free  (Fig.  2B).  What  part  of  the 
seed  grows  most  rapidly?  Do  the  seed- 
leaves  grow  at  all?  What  has  split  the 
seed-covering  across  in  Fig.  2B? 
Notice  how  hard  are  the  coverings  the  little  plant  must 
break  through  in  the  Buckeye,  the  Peach,  and  the  Cocoa- 
nut.  Would  it  not  be  a  great  advantage  if  the  covering 
were  made  softer  or  less  resistant  at  the  spot  where  the 
plant  must  break  through?  Can  you  discover  anything  of 
this  kind?  The  "eyes"  of  the  cocoanut  are  softer  places  in 
the  shell;  the  peach  stone  splits  easily  along  the  edges. 
Peach  stones  take  so  long  to  germinate  that  we  will  study 
the  squash  instead.  Notice  where  the  seed  splits  (Fig.  3) ; 

notice  also  a  peculiarity 
of  the  squash,  a  small 
projection  known  as  the 
"peg"  which  grows  out 
just  at  the  right  place  on 
the  stem.  Can  you  see 
of  what  use  this  peg  is? 
To  watch  a  squash  wrig- 
gling out  of  its  shell 
reminds  one  of  the  way 
a  man  pulls  off  his  boots, 
and  the  peg  corresponds 
to  the  man's  toe  when 
he  makes  it  serve  as  a 
bootjack  (Figs.  3  and 
FIG.  4.  4). 


FIG.  3. 


48 
Getting  into  £.&  soon  as  the  plant  is  fairly  out  of  the  seed-covering, 

the  Ground. 

the  root  begins  to  bore  its  way  downward  into  the  soil. 
Have  you  ever  noticed  what  a  hard  time  the  roots  have  in 
getting  into  the  ground  when  the  seed  happens  to  lie  on  the 
surface?  Put  some  seeds  on  the  surface  of  moist  soil  and 
cover  them  with  a  funnel  (with  a  little  cotton- wool  in  the 
neck  to  retain  the  moisture  and  admit  air)  or  with  an 
inverted  wide-mouthed  bottle,  or,  better  still,  with  a  bell 
jar.  At  first  when  the  root  starts  to  bore  downward  into 
the  soil  it  only  succeeds,  in  many  cases,  in  lifting  the  seed 
up  from  the  earth.  How  does  the  plant  overcome  this 
difficulty!  If  you  look  closely  you  can  see  a  host  of  tiny 
thread-like  hairs  growing  out  from  the  radicle  and  anchor- 
ing the  plant  to  the  soil,  thus  enabling  it  to  penetrate  into  it. 
Getting  above  Have  you  ever  thought  of  the  difficulties  plants  have 
when  the  seeds  are  buried  deeply  underground  and  on 
awakening  and  bursting  their  seed-coverings  they  find  a 
load  of  earth,  which  must  be  struggled  through  or  pushed 
aside  before  they  can  reach  the  light?  Should  you  think 
this  would  be  a  serious  obstacle  to  overcome  ?  Plant  some 
Scarlet  Runner  Beans  in  three  different  pots,  one,  two,  and 
three  inches  deep  respectively,  packing  down  the  earth  well 
above  them .  Thrust  a  smooth  flat  piece  of  wood  into  the 
soil  beside  each  lot  and  write  on  it  with  a  soft  lead  pencil 
the  date  of  planting.  Note  the  date  on  which  the  first 
plants  of  each  lot  appear  above  the  ground.  The  plants 
which  are  deepest  in  the  soil  may  never  come  up  at  all;  or 
if  they  do,  they  may  creep  up  along  the  sides  of  the  pot 
where  the  earth  has  shrunk  away  and  left  a  crack.  Or 
sometimes  they  will  lift  up  the  whole  mass  of  earth  above 
in  a  round,  solid  cake  and  thrust  it  bodily  out  of  the  pot. 
After  witnessing  a  feat  like  this  we  are  more  ready  to  believe 
in  the  tales  of  mushrooms  raising  flagstones  and  the  like. 
We  may  test  the  strength  of  each  plant  individually  by  a 
very  simple  contrivance.  Take  a  small  light  glass  funnel 
(if  this  proves  too  heavy  one  of  tin  may  be  used) ,  close  the 
end  with  a  cork  and  thrust  the  neck  through  the  bottom  of 


49 

a  small  pasteboard  or  paper  box.  This  should  be  placed 
over  the  plant  as  it  emerges  from  the  ground,  and  shot 
may  be  poured  into  the  box  until  the  plant  is  barely  able  to 
raise  the  load. 

Notice  how  much  more   easily  some   plants   come   up 
through  the  ground  than  others ;  the  Corn-plant,  for  instance, 


FIG.  5. 


FIG.  7. 


(Fig.  5)  rolls  its  leaves  up  into  a  sharp,  slender  awl  which 
seems  to  pierce  the  soil  with  ease.  But  the  Scarlet  Runner 
(Figs.  6  and  7)  is  very  clumsy  on  account  of  the  crook  in 
the  stem,  and  must  lift  a  much  greater  load.  Sometimes  it 
pushes  up  great  lumps  of  soil  when  it  comes  to  the  surface. 
What  is  the  use  of  this  crook  in  the  stem?  Let  us  look 
also  at  the  common  Bean  and  at  the  Castor  Bean  (Fig.  8), 
which  do  not  get  out  without  a  struggle  which  reminds  us 
of  an  athlete  straining  every  muscle.  Can  you  tell  why  the 
Castor  Bean  has  so  much  trouble? 


50 


Seed  Leaves 
and  Foliage 
Leaves. 


The  Work  of 
Seed  Leaves. 


Let  us  now  notice  what  the 
plant  does  when  it  gets  above 
ground.  The  Scarlet  Runner 
straightens  out  the  crook  in  its 
stem  and  points  its  tip  straight 
upwards.  Soon  the  new  leaves 
grow  larger  and  we  see  clearly 
that  they  are  not  at  all  like 
the  seed-leaves.  Notice  all  the 
differences  that  you  can.  Here 
are  some  of  them: — Seed-leaves: 
underground;  pale  yellow;  small 
and  thick;  shrivel  and  grow 
smaller  for  some  time,  eventually 
fall  off .  Foliage-leaves: 
above  ground;  bright 
green;  large  and  thin; 
increase  in  size  for  some 
time,  remain  on  the 
plant. 

What  is  the  reason 
for  all  these  differences? 
Of  what  use  are  the  seed- 
leaves  ?  Perhaps  the 
simplest  way  to  answer 
this  is  to  cut  them  off 
and  see  how  the  plant 
gets  along  without  them. 
Select  several  plants 
(about  an  inch  high) 
growing  in  a  pot.  Re- 
move the  seed-leaves 
from  one-half  the  num- 
ber and  tie  pieces  of 
white  twine  to  the  un- 
injured plants  and  red 
twine  to  the  others,  to 


FIG.  8. 


FIG.  9. 


51 

distinguish  them.  In  a  few  days  you  will  see  a  differ- 
ence; later  on  this  will  be  much  more  marked  (see 
Fig.  9).  It  would  seem  that  the  loss  of  the  seed-leaves 
stops  the  growth  of  the  plant.  Why  is  this  so?  We  see 
that  the  longer  the  seed-leaves  remain  on  the  plant 
the  more  they  shrivel;  i.e.,  the  more  substance  they  lose. 
We  cannot  help  thinking  that  the  plant  is  taking  this  sub- 
stance from  the  seed-leaves,  especially  when  we  find  that 
the  principal  substance  in  the  seed-leaves  is  starch,  a  very 
important  food- substance  for  plants.  How  do  we  know  this 
substance  is  starch?  By  means  of  a  very  simple  test  which 
you  may  try  for  yourselves.  Break  a  seed-leaf  in  two  and 
put  a  drop  of  iodine  solution  on  the  broken  surface;  if  it 
turns  dark  blue  (or  black)  it  shows  that  starch  is  present. 
Test  a  little  commercial  starch  in  the  same  way.  This  test 
is  so  simple  and  certain  that  we  can  use  it  whenever  we  wish 
to  know  if  any  part  of  the  plant  contains  starch. 

I  think  we  now  know  the  use  of  the  seed-leaves.  What 
is  the  use  of  the  foliage-leaves?  Do  they  also  contain 
starch?  Let  us  test  them  as  follows:  Let  the  plants  stand 
in  as  strong  light  as  possible  during  the  day;  toward  sun- 
down remove  some  of  the  largest  leaves,  boil  them  (in  order 
to  kill  them  and  swell  the  starch)  and  put  them  in  alcohol 
over  night.  In  the  morning  they  will  appear  bleached,  as 
the  alcohol  has  extracted  the  green  color.  Dissolve  in 
water  some  crystals  of  potassium  iodide  and  add  a  few 
flakes  of  solid  iodine  to  the  solution.  Place  the  leaves  in 
the  solution  and  if  they  do  not  turn  dark  at  once  leave  them 
for  some  hours. 

How  do  the  foliage-leaves  get  their  starch?  Do  they 
get  it  from  the  supply  in  the  seed-leaves,  or  do  they  make  it 
themselves?  Let  us  see  if  we  can  answer  this  question. 
Keep  a  plant  in  darkness  two  or  three  days;  test  the  leaves 
for  starch.  If  none  is  found,  remove  several  leaves  from 
the  plant,  putting  one-half  the  number  in  darkness  for  a 
day  or  two  and  the  rest  where  they  will  get  as  much  light 
as  possible.  The  leaves  must  be  placed  in  water;  be  sure 


52 


that  the  stalks  dip  well  beneath  the  surface.  After  a  day 
or  so  test  the  leaves  which  have  been  in  the  light.  The 
starch  which  we  now  find  in  the  leaves  must  have  been 
made  by  them  after  they  ivere  removed  from  the  plant.  Now 
•test  the  leaves  which  have  been  kept  in  darkness  all  the 
time.  Why  is  there  no  starch  in  them?  Is  it  because  they 
have  been  kept  in  darkness!  We  may  put  this  to  a  final 
test  in  a  very  simple  way.  Fasten  corks  to  opposite  sides 
of  a  leaf,  (as  shown  in  Pig.  10)  so  as  completely  to  exclude 


FIG.  10.  FIG.  11. 

the  light  from  the  covered  portion.  The  leaf  must  not  be 
removed  from  the  plant  and  should  be  placed  where  it  will 
get  plenty  of  light.  In  a  day  or  so  test  it  for  starch;  this 
is  found  everywhere  except  in  the  covered  portion  (Fig.  11) . 
It  would  seem  that  lack  of  light  alone  has  prevented  this 
part  of  the  leaf  from  making  starch.  Foliage  leaves,  then, 
have  the  power  of  making  starch ;  but  they  must  have  light 
in  order  to  do  so. 

Now  what  is  the  use  of  this  starch  in  the  foliage- 
leaves?  Is  it  absorbed  by  the  plant  like  the  starch 
in  the  seed-leaves?  If  so,  ought  we  not  to  find  less 
starch  in  the  leaves  in  the  morning  than  at  night, 
since  the  making  of  starch  stops  at  sundown  and 
what  is  taken  away  during  the  night  cannot  be  replaced 
until  the  next  day?  Test  some  leaves  at  sundown  or 
a  little  before;  now  place  the  plant  in  a  dark  box  or  cup- 
board, and  in  the  morning  test  again.  We  find  the  starch 


has  almost  or  quite  disappeared.  Would  it  have  done  so  if 
the  leaves  had  not  been  on  the  plant?  Take  some  leaves 
which  contain  plenty  of  starch;  remove  them  from  the 
plant  and  put  them  in  a  dark  box  or  cupboard.  The  stalks 
should  dip  well  under  water.  In  a  day  or  so  test  them  for 
starch.  They  have  not  lost  any.  It  seems  then  that 
foliage  leaves  produce  starch  and  the  plant  absorbs  it  from 
them, 

It  is  now  time  to  see  whether  we  can  answer  the  question 
asked  a  little  while  ago,  Why  are  the  foliage-leaves  and 
seed-leaves  so  different?  You  can  see  that  it  is  of  advantage 
to  the  plant  to  have  the  foliage-leaves  remain  as  long  as 
possible  on  the  plant.  You  can  also  see  why  they  should 
have  as  large  a  surface  as  they  can,  since  the  more  light 
they  catch  the  more  starch  they  can  make.  You  can  see, 
too,  why  the  seed-leaves  need  to  be  thick  and  bulky  so  as  to 
store  up  a  great  deal  of  starch. '  Perhaps  you  do  not  see 
why  the  foliage-leaves  are  green  and  the  seed-leaves  pale 
yellow.  You  will  understand  this  if  you  put  a  few  seeds 
into  a  pot  containing  soil  or  sawdust  and  keep  it  entirely  in 
the  dark  until  the  plants  are  several  inches  high.  The 
plants  grow  very  tall  and  slender  and  the  leaves  are  small 
and  yellow,  in  color  resembling  the  seed-leaves.  Put  the 
plants  in  the  light  for  a  day  or  so.  Test  them  for  starch. 
None  is  found.  Leave  them  in  the  light  until  they  turn 
green.  Then  test  for  starch.  Does  the  result  indicate  that 
the  green  substance  is  necessary  for  making  starch?  It 
is  this  substance,  called  chlorophyll,  which  is  extracted 
by  the  alcohol  when  you  test  the  leaves  for  starch.  Usually 
it  is  not  formed  in  darkness.  Do  you  now  see  why  the 
seed-leaves  are  not  green?  Remove  some  of  the  earth  so  as 
to  expose  them  to  the  light.  Do  they  turn  green? 

The  seed-leaves  and  foliage-leaves  are  different  because 
they  have  different  tasks  to  perform,  and  their  structure 
must  be  adapted  to  the  special  kind  of  work  they  have  to 
do.  We  may  sum  this  up  by  saying,  function  determines 
structure.  When  we  see  how  different  the  seed-leaves  of 


54 


FIG.  12. 


the  Castor  Bean  are  from  those  of  the  Scarlet  Runner,  for 
example,  we  at  once  suspect  that  their  tasks  must  be 
quite  different.  Notice  how  thin  and  delicate  are  the  seed- 
leaves  of  the  Castor  Bean 
(Fig.  12).  Where  is  the 
food  stored  in  the  Castor 
Bean?  Not  in  the  seed-leaves 
but  around  them,  and  their 
task  is  merely  to  absorb  it. 
See  how  closely  they  are 
attached  to  the  substance  they 
are  absorbing.  Cut 
away  the  food  sub- 
stance carefully,  so 
as  not  to  injure  the 
seed-leaves.  Does  this 
check  the  growth  of 
the  plant?  After  the 
seed-leaves  get  above 
ground  they  are  called 
upon  to  do  still  an- 
other kind  of  work. 
What  is  it?  Do  they 
change  their  appear- 
ance correspond- 
ingly? (See  Fig.  13). 
Do  you  know  any 
other  seed-leaves 
which  are  absorbing 
organs  instead  of 
storehouse  s — a  n  y 
which  are  both?  (See 
Fig.  5).  Do  you 
know  any  other  seed- 
leaves  which  come 
above  ground  and 
Pio.  13.  help  to  make  starch? 


55 

Every  part  of  the  plant  has  its  work  to  do  and  its  whole  The  work  of 
structure  is  expressly  adapted  to  this  work.  Notice  the  root,  the  Root- 
for  instance.  See  the  multitude  of  tiny  hairs  which  help  it 
to  absorb  water  and  food.  Where  the  root  is  covered  with 
these  hairs  the  absorbing  surface  is  ten  to  twenty  times  as 
great  as  elsewhere.  Notice  the  root- cap  which  protects  the 
delicate  tip  as  it  is  driven  downward  into  the  soil.  (Roots 
allowed  to  develop  between  pieces  of  moist  blotting  paper 
show  the  hairs  well;  cuttings  of  Wandering  Jew  placed  in 
water  develop  roots  which  show  both  the  cap  and  the  hairs 
admirably) .  Is  the  root  driven  down  into  the  soil  with  much 
force?  We  may  find  out  by  a  very  simple  contrivance. 
Remove  the  top  and  bottom  from  a  shallow  wooden  box. 
Replace  the  bottom  by  wire- netting  with  meshes  about  one- 
quarter  of  an  inch  square.  Cover  this  with  a  piece  of 
tin-foil  and  on  this  place  enough  earth  to  fill  the  box. 
Place  seeds  in  this  and  suspend  the  box  at  a  convenient 
height  so  that  when  the  roots  come  through  the  bottom 
they  can  be  easily  observed.  How  thick  a  piece  of  tin-foil 
will  they  penetrate"?  Try  different  kinds  of  seeds. 

What  drives  the  root  downward  with  so  much  force?    HOW  Roots 
Why  are  not  the  side  roots  torn  off  as  the  root  moves  down-   *nd  Stems 

*  t  Grow. 

ward?  We  may  answer  both  these  questions  by  marking  a 
root  with  ink-dots  (waterproof  ink  is  best;  it  should  be  put 
on  with  a  small  brush)  about  one- sixteenth  of  an  inch  apart 
and  allowing  it  to  develop  in  water.*  We  shall  then  see  the 
marks  separate  near  the  tip,  showing  that  the  root  is 
elongating  there,  while  higher  up  is  a  region  where  they  do 
not  separate.  It  is  only  in  this  upper  region  that  the  side 
roots  come  out. 

Does  the  stem  have  a  similar  elongating  region?  Where 
are  the  new  leaves  formed?  What  would  happen  to  the 
stem  if  this  elongating,  formative  region  were  removed? 
Select  Scarlet  Runner  seedlings  about  two  inches  high 


*  Tie  a  piece  of  cheese-cloth  over  the  mouth  of  a  tumbler;  thrust  the  root 
through  it;  pour  in  water  until  the  seed-leaves  are  partly  submerged  and 
invert  a  second  tumbler  over  the  first. 


56 


Why  the  Root 
Grows  Down- 
ward. 


(above  ground)  and  cut  off  the  stem  below  the  first  pair  of 

foliage-leaves.     In  a  few  days  you  will  see  new  stems  or 

branches    starting  out.     Where  do  they   appear   to   come 

from?     (See  Fig.  14).     In  a  short 

time    these    will    be    followed   by 

others  until  a  dozen  or  more  are 

growing  up  to  take  the  place  of  the 

one  which  has  been  removed.     Try 

the  same  experiment  on  other  kinds 

of  plants.     Now  let  us  remove  the 

elongating  region  of  the  root  and 

see    what   will   happen.     Do    new 

roots  come  out?     Where?     Do  they 

grow    horizontally    like    the    side 

roots  or  straight  downward  like  the 

main  root?     The  roots  should  be 

allowed  to  develop  in  water  so  as  to 

be  easily  observed. 

Does  the  main  root  always  grow 
straight  downward?  Try  placing 
the  seed  in  various  positions  to  see 
if  this  affects  the  direction  of 
growth.  The  seeds  may  be  placed 
on  the  surface  of  moist  earth  (and 
covered  as  described  above)  or  may 
be  pinned  on  corks  in  various 
positions,  and  the  corks  may  float 
on  the  surface  of  the  water  in  a 
shallow  dish.  A  little  cotton  laid  over  the  seed-leaves  and 
dipping  in  water  will  keep  them  moist.  After  the  root  has 
grown  a  little,  change  the  position  of  the  seed  so  that  the 
root  points  straight  upward  or  is  horizontal.  Does  it  begin 
to  grow  down  again  ?  Why  does  the  main  root  persist  in 
growing  downward  no  matter  in  what  position  the  seed  may 
be  placed  ?  The  idea  has  been  put  forward  that  the  root 
tip  not  being  very  rigid  droops  downward  of  its  own  weight, 
and  this  starts  the  growth  in  the  right  direction.  This 


FIG.  14. 


57 

idea  can  be  tested  by  a  very  simple  experiment.  In  a  small 
glass  dish  place  some  mercury ;  split  a  cork  and  fasten  it  to 
the  side  of  the  dish  (Fig.  15).  To  this  pin  a  germinating 

seed  with  a  perfectly  straight 
radicle  about  an  inch  in  length . 
Place  the  radicle  in  a  hori- 
zontal position  and  resting  on 
the  surface  of  the  mercury. 
Pour  on  enough  water  to  par- 
FlG-  15>  tially  submerge  the  seed.  In 

a  few  hours  the  root-tip  will  bend  downwards  and  pene- 
trate the  mercury,  overcoming  its  resistance  (Fig.  15). 
It  would  seem  that  gravity  must  determine  the  downward 
growth  of  the  root.  Now,  if  this  be  so,  what  would  happen 
if  we  make  the  force  of  gravity  of  no  effect  by  placing  the 
seed  on  a  revolving  wheel  ?  If  the  wheel  turns  always  at 
the  same  rate,  each  side  of  the  root  will  feel  the  downward 
pull  of  gravity  for  a  short  time,  but  no  side  will  feel  it 
more  than  another.  So  when  all  sides  are  equally  affected, 
will  the  root  have  any  tendency  to  bend  in  one  direction 
more  than  another?  Let  us  see.  The  construction  of  the 
wheel  is  a  very  simple  matter.  Have  a  plumber  or  tinsmith 
cut  out  of  thin  sheet  zinc  a  circular  piece  six  inches  in 
diameter.  Have  this  cut  to  allow  the  insertion  of  corks  as 
shown  in  Fig.  16.  Let  the  flaps  made  by  cutting  remain 
in  place.  Fix  round,  flat  corks  in  the  cut  places,  and  bend 
the  flaps  so  as  to  support  the  corks  as  firmly  as  possible. 
For  the  axle  use  a  knitting  needle,  impaling  two  rubber 
corks  upon  it,  one  on  each  side  of  the  zinc  disc  (Fig.  16,  A) 
to  hold  the  latter  in  place.  They  should  press  firmly  against 
the  disc  to  insure  its  turning  with  the  axle.  Two  upright- 
wooden  supports  fastened  to  a  block  of  wood  are  pierced 
by  holes  just  large  enough  to  admit  small  glass  tubes  in 
which  the  axle  rests.  One  of  these  (Fig.  16,  C)  is  closed 
at  one  end  to  keep  the  axle  from  slipping  too  far;  the  other 
(Fig.  16,  B),  being  open  at  both  ends,  allows  the  axle  to 
pass  through,  and  (being  bent  at  a  right  angle  as  shown  in 


58 

the  figure)  to  be  fastened  by  fine  wire  to  the  minute-hand 
of  a  clock.  This  apparatus,  which  almost  anyone  can  easily 
make  in  a  little  while,  permits  of  some  exceedingly  inter- 
esting experiments,  and  answers  the  purpose  as  well  as  a 
costly  instrument.  Select  some  peas  with  radicles  about 
half  an  inch  long;  partially  envelop  each  one  in  wet  cotton 


FIG.  16. 


and  pin  them  upon  the  corks.  Arrange  a  saucer  of  water 
so  that  as  the  wheel  revolves  the  seeds  will  dip  into  it  and 
be  kept  moist.  The  seed  itself  need  not  come  in  contact 
with  the  water,  but  a  little  strip  of  cloth  or  filter  paper 
may  be  arranged  so  as  to  hang  down  from  the  seed  and 
touch  the  water.  The  clock  is  set  agoing  and  the  wheel 
revolves  once  an  hour.  The  seeds  grow  well  under  these 
conditions,  but  the  direction  of  growth  is  no  longer  the 


59 

same  for  all  the  roots.  Instead  they  may  grow  in  almost 
any  way.  Often  we  see  some  of  them  turn  and  grow  in  the 
same  direction  as  the  stem.  How  do  the  stems  behave? 
The  directing  power  of  gravity  being  removed,  both  stems 
and  roots  grow  in  quite  haphazard  fashion. 

We  may  now  go  a  step  further  and  substitute  a  new 
force  for  that  of  gravity.  This  we  may  do  by  making  the 
wheel  revolve  more  rapidly.  If  you  bend  a  piece  of  wire 
around  the  spoke  of  a  wheel,  so  as  to  form  a  loose  ring, 
and  spin  the  wheel  rapidly,  the  ring  will  be  violently  hurled 
to  the  rim  of  the  wheel  by  a  force  commonly  called  centri- 
fugal force.  If  the  wheel  be  revolved  rapidly  enough  the 
centrifugal  force  will  be  much  greater  than  the  force  of 
gravity.  Will  a  seed  placed  on  such  a  wheel  direct  its 
roots  in  accordance  with  the  centrifugal  force !  To  test 
this  we  remove  the  clock  and  saucer,  place  the  apparatus  in 
a  sink,  and  attach  the  rubber  tube,  T,  to  a  faucet.  At  the 
end  of  this  tube  is  a  piece  of  glass  tubing.  S,  drawn  to  a 
point.  The  manner  in  which  this  is  supported  is  shown  in 
the  figure.  It  should  be  wedged  firmly  in  place  by  wooden 
wedges,  and  be  directed  so  that  the  stream  will  strike  the 
Avheel  just  at  its  rim.  The  stream  must  be  powerful 
enough  to  make  the  wheel  revolve  rapidly.  A  piece  of 
cloth  must  be  put  over  and  around  it,  like  a  tent,  to  confine 
the  flying  drops.  In  the  course  of  a  day  or  so,  provided 
the  wheel  is  turning  rapidly  enough,  we  shall  see  the  roots 
all  bending  away  from  the  center  of  the  wheel  and  growing 
straight  out  in  the  direction  of  the  radius,  while,  on  the 
other  hand,  the  stems  grow  straight  in,  pointing  their  tips 
toward  the  center  of  the  wheel. 

Let  us  see  what  will  happen  if  we  place  the  apparatus 
on  its  side  so  that  the  wheel  revolves  horizontally,  the 
closed  tube,  C,  being  below.  If  the  plants  have  become 
inconveniently  large  we  may  replace  them  by  fresh  ones 
with  radicles  about  an  inch  long.  Two  forces  now  act  on 
the  plants,  the  centrifugal  force  and  that  of  gravity.  The 
roots  take  up  an  intermediate  position,  growing  away  from 


60 

the  center  of  the  wheel  as  before,  but  also  obliquely  down- 
ward; the  stems  grow  in  an  exactly  opposite  direction. 

These  experiments  lead  us  to  think  that  when  the  root 
and  stem  issue  from  the  seed,  gravity  determines  the  direc- 
tion in  which  they  grow.  And  so  we  can  understand  how 
the  seed,  whether  above  ground  or  below,  unerringly  sends 
its  stem  and  root  in  the  right  directions.  We  can  easily 
understand  that  this  is  a  very  important  matter  for  the 
plant,  for  the  quicker  it  gets  its  stem  above  ground,  into 
the  light  and  air,  and  its  roots  down  into  the  soil  to  find 
food  and  moisture,  the  better  will  be  its  chances  of  living 
through  this  first  period  of  its  independent  life,  which  is 
more  critical  and  beset  with  dangers  than  any  other. 

The  root  goes  down  into  the  ground  to  seek  for  water. 
Sometimes  we  find  drains  or  cisterns  choked  by  roots 
which  have  grown  into  them  from  trees  many  yards  away. 
This  leads  us  to  suspect  that  roots  seek  for  water.  Can 
you  think  of  any  way  to  test  this  idea!  Here  is  a  very 
simple  one,  but  you  may  think  of  one  equally  good.  A 
glance  at  Fig.  17  will  explain  it.  The-  seeds  have  been 


FIG.  17. 


planted  in  damp  sawdust,  in  a  box  with  a  bottom  made  of 
wire-netting.  The  roots,  growing  straight  down  at  first, 
meet  the  dry  air  and  turn  back,  some  of  them  at  least,  to 


(51 


Seek  Light? 


the  damp  sawdust.  In  this  case  moisture  seems  to  be  more 
powerful  than  gravity  in  directing  their  growth,  and  we 
can  readily  see  that  this  is  of  advantage  to  the  root,  since 
its  function  is  to  seek  and  absorb  water. 

Now  the  stem  goes  above  ground  to  seek  light.  Does  DO  stems 
it  have  the  power  of  growing  toward  the  light  as  the  root 
does  toward  moisture.  Can  you  think  of  a  way  to  answer 
this  question  ?  The  easiest  way  is  to  cover  the  plant  and 
the  pot  in  which  it  is  growing  with  a  box,  and  make  a  hole 
at  one  side  to  admit  light.  Then  if  the  plants  have  any 
tendency  to  grow  toward  the  light,  it  ought  to  show  itself. 

The  result  of  this  experiment  is 
shown  in  Fig.  18;  in  this  case  a 
Scarlet  Runner  was  placed  in  a 
wooden  box,  one  side  of  which 
is  removed  to  show  the  plant. 
Radishes  are  good  for  this  experi- 
ment. They  come  up  quickly 
and  are  very  sensitive  to  the 
light.  We  must  not  forget  that 
the  whole  object  of  seeking  light 
is  to  expose  the  leaves  to  it.  In 
what  position  will  they  catch  the 
most  light?  Do  you  generally 

find  leaves  in  this  position  f  Observe  all  the  plants  you  can 
out  of  doors  to  see  how  their  leaves  are  placed.  Notice 
especially  plants  growing  near  walls  or  houses,  or  in  any 
position  where  they  get  the  light  from  one  side  only.  Do 
you  find  the  leaves  facing  the  side  from  which  the  light 
comes  ?  Is  this  arrangement  due  to  the  light  itself  ? 
Grow  some  Nasturtiums  in  pots  and  place  them  in  a  box 
which  admits  the  light  on  one  side  only.  When  the  leaves 
have  all  turned  so  as  to  face  the  light,  turn  the  plant 
around  so  that  they  face  away  from  it.  How  long  is  it 
before  they  begin  to  turn  back  again  ?  Try  them  before  a 
window  in  the  same  way. 


FIG.  18. 


Do  Leaves 
Seek  Light? 


62 


The  English  Ivy  (Fig.  19)  is  interesting  to  experiment 
with;  but  it  takes  too  long  to  grow  it  in  pots,  so  we  will  use 
a  quicker  method.  Find  some  plants  grow- 
ing where  they  get  plenty  of  light,  and 
bending  back  some  of  the  branches  tie 
them  so  that  the  side  that  was  shaded 
before  now  gets  the  light.  How  do  the 
young  leaves  place  themselves  ?  On  which 
side  do  the  new  roots  come  out  ?  Where 
do  the  new  leaves  appear  ?  Does  this  indi- 
cate that  light  influences  roots  as  well  as 
stems  and  leaves  ?  The  Nasturtium  leaves 
turn  to  the  light  much  faster  than  the  Ivy 
leaves,  but  there  are  others  which  move 
still  faster.  If  you  watch  the  leaves  of  the 
Lupine,  you  will  see  that  they  follow  the 
sun  all  day  long,  facing  east*  in  the  morn- 
ing and  west*  in  the  evening.  Can  you 
find  any  other  plants  which  do  this  ?  Are 
there  any  flowers  which  behave  in  this  way  ? 
It  must  be  a  great  advantage  to  the  plant  to  have  its 
leaves  following  the  sun  in  this  way,  for  of  course  they  must 
get  much  more  light.  But  most  plants  must  be  content  to 
have  their  leaves  remain  in  one  position,  or  at  least  move 
very  slowly  indeed.  It  is,  then,  all  the  more  important  to 
have  the  leaves  placed  in  the  most  favorable  way  possible. 
If  they  are  crowded  one  above  another,  they  will  keep  each 
other  from  getting  the  light  they  need  for  making  starch. 
Can  you  find  any  indications  of  a  skillful  arrangement  for 
avoiding  this  !  Look  at  a  branch  of  the  Chestnut  (Fig.  20) 
or  Ivy-leaved  Geranium  (Fig.  21)  and  notice  how  the  leaves 
are  placed.  Do  they  shade  each  other  ?  This  arrangement 
has  been  called  a  leaf -mosaic.  Do  you  see  why !  Can 
you  explain  how  this  clever  arrangement  is  brought  about  ? 
What  are  the  best  leaf-mosaics  you  can  find  ? 


FIG.  19. 


*i.e.,  Northeast  or  -west,  or  southeast  or  -west,  according  to  the  season. 


63 


FIG.  20. 


FIG.  21 


64 

A  Life-long  ^6  have  scarcely  made  a  beginning  of  our  experiments, 

yet  they  have  already  led  us  into  the  fields  to  study  plants 
as  we  find  them .  Here  there  is  always  something  of  interest 
for  eyes  which  have  learned  to  see.  With  a  little  guidance 
the  child  learns  to  see  more  and  more  for  himself,  and 
strives  more  and  more  to  see  aright,  to  draw  and  describe 
things  as  they  really  are.  So  the  love  of  nature  leads  him 
to  the  love  of  truth.  These  twin  influences,  upbuilding 
both  mind  and  character,  should  come  early  to  the  child 
and  be  a  lifelong  inspiration. 


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